No other English prefix produces more new words than un-. Every word that starts with un is one of two kinds. In the first, un- negates an adjective, so fair becomes unfair. In the second, un- reverses a verb, so lock becomes unlock. Tell the two apart and you know what a new un- word means at first sight. The everyday un- words you already read and hear are the first place to apply that.
Common Words That Start With Un
Un- is the most productive prefix in English. Before an adjective or a noun it means not, as in unfair and unrest. Before a verb it reverses or removes, as in untie and uncork. The two senses take the same spelling, and the word class of the base word shows which one applies.
- Unable: not able to do something.
- Unaware: not knowing that something has happened.
- Uncertain: not decided, or not sure of the answer.
- Uncomfortable: physically uneasy, or awkward in a situation.
- Uncommon: rare enough that you notice it.
- Uncover: to take a cover off, or to find something hidden.
- Undo: to reverse what was already done.
- Undress: to take clothes off.
- Uneasy: slightly worried without a named reason.
- Unemployed: without paid work.
- Unexpected: arriving without warning.
- Unfair: not treating everyone by the same rule.
- Unfold: to open something that was folded, or to happen over time.
- Unhappy: sad, or dissatisfied with a result.
- Unhealthy: bad for the body, or in poor health.
- Unkind: cruel rather than merely lacking kindness.
- Unknown: not identified, or not familiar to anyone.
- Unlikely: improbable, though still possible.
- Unlock: to open a lock, or to make something available.
- Unlucky: meeting bad luck through no fault of your own.
- Unpack: to take contents out of a bag or box.
- Unsafe: dangerous to anyone standing close by.
- Untidy: messy, with nothing put away.
- Unusual: different from what normally happens.
- Unwind: to unroll something wound up, or to relax.
What The Prefix Un Means
Dictionaries print two separate headwords for un-, and both spellings are identical. In its negative sense, un- descends from Old English and matches Latin in- and Greek a-. The reversing un- traces instead to a different Old English prefix, on(d)-, which matches German ent-. By Middle English the two had merged into a single form, which is why the same two letters now mark two different grammatical functions.
Check the word class of the base word before you decide what an un- word means. An adjective takes the negative sense. With a verb, the reversing sense applies. One check of the word class is enough for almost every un- word in English, including ones you meet for the first time.
Un Meaning Not
Attached to an adjective or a noun, un- negates what the base word means.
| Base word | Word with un |
|---|---|
| Fair | Unfair |
| Happy | Unhappy |
| Kind | Unkind |
| Clear | Unclear |
| Safe | Unsafe |
| Rest | Unrest |
The negative un- is stronger than non-. Unkind names active cruelty, while non- would name a plain absence, and un-American implies hostility rather than a neutral difference of nationality. Choose un- when you want the judgement, and non- when you want the bare fact.
Un Meaning Reverse Or Remove
Attached to a verb, un- reverses the action or removes something.
| Base verb | Word with un |
|---|---|
| Lock | Unlock |
| Tie | Untie |
| Pack | Unpack |
| Fold | Unfold |
| Cork | Uncork |
| Plug | Unplug |
The reversal happens in two ways. Untie and unfold reverse an action you performed a moment earlier. In uncork and unmask, un- removes a specific thing, so the noun after it names what goes away. In past participles the two senses overlap, since unrigged means both that the rigging was taken down and that no rigging is present.
Words That Start With Un That Are Not Prefixes
Some words begin with the letters un and contain no prefix. Most descend from Latin unus, meaning one, so the un in them means single rather than not. Splitting these words at un- produces nonsense, which is the fastest way to spot them.
- Uncle: from Latin avunculus, a mother’s brother. No base word cle exists.
- Under: an Old English preposition, complete in itself.
- Unicorn: from Latin unus and cornu, meaning one horn.
- Uniform: from unus and forma, meaning one shape for everyone.
- Union: a joining of separate parts into one.
- Unique: one of a kind, with no second example.
- Unison: two or more voices at one pitch.
- Unit: a single measured amount.
- Unite: to join separate parts into one whole.
- Unity: the state of being one.
- Universe: everything turned into one whole.
- University: a body of scholars treated as one community.
- Until: an Old English compound of und and till.
The same Latin root produces unanimous and unify, two more of the words that start with U that no reader should split at the prefix.
3 Letter Words That Start With Un
Only two three-letter words begin with un, and both are clipped forms of longer words.
- Uni
- Uns
4 Letter Words That Start With Un
- Unai
- Unau
- Unbe
- Unce
- Unci
- Unco
- Unde
- Undo
- Undy
- Unis
- Unit
- Unto
Two of these name animals. An unau is a two-toed sloth and an unai is a three-toed sloth, and both score well when the board is tight.
5 Letter Words That Start With Un
- Unapt
- Unarm
- Unary
- Unbag
- Unban
- Unbar
- Unbox
- Uncap
- Uncle
- Uncos
- Uncut
- Under
- Undid
- Undue
- Unfed
- Unfit
- Unfix
- Unify
- Union
- Unite
- Units
- Unity
- Unlit
- Unman
- Unmet
- Unmix
- Unpeg
- Unpin
- Unrig
- Unrip
- Unsay
- Unset
- Unsex
- Untie
- Until
- Unwed
- Unwit
- Unzip
Wordle players want the ones with common letters, so you learn more from untie, until, unite, under and unity than from unzip. The wider set is in the five-letter words that start with U.
6 Letter Words That Start With Un
- Unable
- Unbend
- Unbind
- Unbolt
- Unborn
- Unbury
- Uncoil
- Uncork
- Uncurl
- Undead
- Undies
- Undock
- Undone
- Unduly
- Unease
- Uneasy
- Uneven
- Unfair
- Unfold
- Unfurl
- Unglue
- Unholy
- Unhook
- Unhurt
- Unique
- Unisex
- Unison
- United
- Unjust
- Unkind
- Unknit
- Unknot
- Unlace
- Unless
- Unlike
- Unlink
- Unload
- Unlock
- Unmade
- Unmask
7 Letter Words That Start With Un
- Uncanny
- Uncivil
- Unclean
- Unclear
- Uncouth
- Uncover
- Uncross
- Uncrown
- Undated
- Undergo
- Undoing
- Undress
- Undying
- Unearth
- Unequal
- Unfazed
- Unfunny
- Ungodly
- Unguent
- Unhappy
- Unheard
- Unhinge
- Unhitch
- Unhorse
- Unicorn
- Uniform
- Unkempt
- Unknown
- Unlatch
- Unleash
- Unlearn
- Unlevel
- Unlucky
- Unmoved
- Unnamed
- Unnerve
- Unquiet
- Unquote
- Unravel
- Unready
8 Letter Words That Start With Un
- Unabated
- Unafraid
- Unawares
- Unbeaten
- Unbelief
- Unbiased
- Unbidden
- Unbroken
- Unbuckle
- Unbundle
- Unburden
- Unbutton
- Uncaring
- Uncaught
- Uncommon
- Uncouple
- Unctuous
- Undoable
- Undulate
- Unearned
- Unedited
- Unending
- Unerring
- Unevenly
- Unfairly
- Unfasten
- Unfetter
- Unfilled
- Unforced
- Unformed
- Unframed
- Unfreeze
- Unfriend
- Unfrozen
- Unfunded
- Unfurled
- Ungainly
- Ungentle
- Ungifted
- Unguided
Two words here differ from the rest. Unctuous contains no base word ctuous, and it means oily in manner rather than not something. Unfriend entered general dictionaries only after social networks made the action possible, and it takes the reversing sense.
9 Letter Words That Start With Un
- Unabashed
- Unadorned
- Unadvised
- Unaltered
- Unanimous
- Unashamed
- Unassured
- Unbalance
- Unbeknown
- Unbending
- Unblessed
- Unbounded
- Unbridled
- Uncertain
- Unceasing
- Unchained
- Unchanged
- Uncharted
- Unchecked
- Unclothed
- Unclouded
- Uncounted
- Uncoupled
- Uncovered
- Uncrowned
- Undamaged
- Undaunted
- Undecided
- Undefiled
- Undefined
- Underline
- Undermine
- Underpass
- Underside
- Undertake
- Undertone
- Underwear
- Undiluted
- Undivided
- Undoubted
10 Letter Words That Start With Un
- Unabridged
- Unaffected
- Unanswered
- Unassisted
- Unassuming
- Unattached
- Unattended
- Unavailing
- Unbalanced
- Unbearable
- Unbeatable
- Unbecoming
- Unbeliever
- Unblinking
- Unblushing
- Unbuttoned
- Uncensored
- Unchanging
- Uncommonly
- Uncritical
- Undefeated
- Undefended
- Undeniable
- Underlying
- Understand
- Understate
- Understood
- Understudy
- Undertaker
- Undervalue
- Underwater
- Underworld
- Underwrite
- Undeserved
- Undisputed
- Undulating
- Uneducated
- Unemployed
- Unequalled
- Uneventful
11 Letter Words That Start With Un
- Unashamedly
- Unavoidable
- Unblemished
- Uncertainty
- Uncluttered
- Uncommitted
- Unconcerned
- Unconnected
- Unconquered
- Unconscious
- Uncontested
- Unconverted
- Uncorrupted
- Uncountable
- Undemanding
- Underground
- Undergrowth
- Understated
- Undertaking
- Underwriter
- Undesirable
- Undeveloped
- Undignified
- Undisclosed
- Undisguised
- Undisturbed
- Undoubtedly
- Unemotional
- Unflinching
- Unforgiving
12 Letter Words That Start With Un
- Unacceptable
- Unaccustomed
- Unattainable
- Unattractive
- Unbelievable
- Unchallenged
- Unchangeable
- Uncharitable
- Unconvincing
- Uncontrolled
- Undetermined
- Undiminished
- Undiplomatic
- Undiscovered
- Undocumented
- Unemployment
- Unencumbered
- Unforgivable
- Unfrequented
- Ungovernable
- Unhesitating
- Unidentified
- Unimaginable
- Uninterested
- Unmistakable
- Unnoticeable
- Unobtainable
- Unpardonable
- Unprofitable
- Unquestioned
Longer words show these same suffix patterns, which you can check against these twelve letter words.
Short Words That Start With Un
The shortest un- words score fast in Scrabble and fit a tight Wordle grid.
- Uni
- Uns
- Undo
- Unit
- Unto
- Unfit
- Unfix
- Unite
- Unity
- Unzip
Long Words That Start With Un
In long un- words the prefix goes onto a base that already ends in two or three suffixes.
- Uncharacteristically (20 letters)
- Unconstitutionally (18 letters)
- Uncharacteristic (16 letters)
- Uncompromisingly (16 letters)
- Unconditionally (16 letters)
- Unconstitutional (16 letters)
- Undernourishment (16 letters)
- Undistinguished (15 letters)
- Unexceptionable (15 letters)
- Unsophisticated (15 letters)
Positive Words That Start With Un
The negative sense makes these words surprising, since each one negates a bad quality rather than a good one.
- Unafraid: facing something without fear.
- Unbeaten: never defeated in a contest.
- Unbiased: judging without favouring either side.
- Unbroken: whole, or continuing without a gap.
- Unconditional: given with no terms attached.
- Undaunted: still confident after a setback.
- Unfailing: reliable every single time.
- Unflappable: calm when everyone else panics.
- Unhurt: free of injury after an accident.
- Unique: the only one of its kind.
- Unruffled: composed under pressure.
- Unselfish: putting other people first.
- Unshakable: firm no matter what challenges it.
- Unstoppable: impossible to halt.
- United: joined behind one purpose.
Negative Words That Start With Un
- Unclear: hard to understand as written or said.
- Uneasy: anxious without a definite cause.
- Unfair: applying different rules to different people.
- Ungrateful: showing no thanks for a kindness received.
- Unhappy: sad, or dissatisfied with an outcome.
- Unhealthy: damaging to the body over time.
- Unjust: wrong by the standard of fairness itself.
- Unkind: deliberately hurtful to someone.
- Unlucky: suffering bad outcomes by chance.
- Unpleasant: disagreeable to experience.
- Unreliable: failing to do what was promised.
- Unsafe: able to injure someone who comes near it.
- Unstable: liable to fall over, or to change without warning.
- Untidy: disordered and left unarranged.
- Unwanted: received by someone who did not ask for it.
Adjective Words That Start With Un
Most un- words are adjectives, which is why the negative sense outnumbers the reversing one.
- Unable
- Unaware
- Uncertain
- Uncommon
- Unequal
- Unexpected
- Unfamiliar
- Unfit
- Unfriendly
- Unknown
- Unlikely
- Unnecessary
- Unofficial
- Unpopular
- Unrelated
- Unsuitable
- Unsure
- Unusual
- Unwilling
- Unwise
For adjectives beyond the un- family, work through the descriptive words that start with U.
Words That Start With Un To Describe Someone
Each of these adjectives names a specific trait, which makes them stronger than nice or difficult in a report, a reference, or a character sketch.
- Unassuming: modest about real ability.
- Uncanny: strangely accurate in a way that unsettles people.
- Uncaring: indifferent to how other people feel.
- Unconventional: ignoring the normal way of working.
- Undaunted: unafraid after a hard experience.
- Unflappable: steady in a crisis.
- Unforgiving: refusing to let an offence go.
- Ungrateful: taking help without acknowledging it.
- Unhurried: working at a calm pace by choice.
- Unpretentious: honest about who they are.
- Unreliable: poor at keeping promises.
- Unruly: resisting rules and instructions.
- Unselfish: generous with time and attention.
- Unshakable: unmoved by pressure or doubt.
- Unyielding: refusing to compromise on a position.
Action Words That Start With Un
Every verb here takes the reversing sense of un-. Remove the prefix and the action that came first remains, so unwrap only makes sense once something was wrapped.
- Uncork
- Uncover
- Undo
- Undress
- Unfasten
- Unfold
- Unhook
- Unlace
- Unleash
- Unload
- Unlock
- Unpack
- Unplug
- Unroll
- Unscrew
- Unseal
- Untangle
- Untie
- Unwind
- Unwrap
Words That Start With Un And End With Able
The -able ending shows that an action cannot be done, since un- negates the whole adjective rather than the verb inside it.
- Unable
- Unavailable
- Unavoidable
- Unbearable
- Unbeatable
- Unbelievable
- Unbreakable
- Uncomfortable
- Uncountable
- Undeniable
- Unforgettable
- Unreasonable
- Unreliable
- Unsuitable
- Unthinkable
Words That Start With Un And End With Ed
Past participles show both senses at once, which is why unopened means the box was never opened and unlocked means someone opened the lock.
- Unarmed
- Unasked
- Unbeaten
- Uncovered
- Undressed
- Unexpected
- Unfinished
- Unlocked
- Unmarked
- Unopened
- Unpacked
- Untied
Words That Start With Un And End With Ing
- Unassuming
- Unbecoming
- Unblinking
- Unchanging
- Undoing
- Unending
- Unflinching
- Unforgiving
- Unnerving
- Unsettling
- Unwavering
- Unyielding
Words That Start With Un And End With E
- Unable
- Uncle
- Undue
- Unease
- Unique
- Unite
- Unmade
- Unripe
- Unsafe
- Unsure
- Untrue
- Unwise
Un Or In: Which Negative Prefix To Use
Five negative prefixes in English all mean not: un-, in-, im-, il- and ir-. Learners pick the wrong one because the choice depends on the base word rather than on meaning. Three rules apply to almost every case.
Spelling governs three of them: il- goes before l, ir- before r, and im- before m or p. These are spelling rules rather than meaning rules.
- Illegal, illegible, irregular, irrational, impossible, impatient, immature.
Origin governs the other two: in- goes before most Latin borrowings, and un- before most native English words.
- Incorrect, inaccurate, invisible, incapable.
- Unkind, unhappy, unfair, unwell.
A few base words take one prefix only: the wrong one produces a form nobody writes.
- Unpossible ❌ The base word came into English from Latin, so it takes im-: impossible.
- Impossible ✅ This is the standard form in every kind of written English.
- Inhappy ❌ Happy is native English, so it takes un-.
- Unhappy ✅ Unhappy has been the standard form since Middle English.
When two forms genuinely exist, they differ in meaning, so they are not interchangeable. Unfamous means only that something is not well known, while infamous means well known for something bad.
How Many Words Start With Un
The Official Scrabble Dictionary records 4,028 words beginning with un, ranging from two letters to fifteen. Broader word finders built on general dictionaries return roughly 9,489, since they admit inflections and technical terms that tournament play excludes.
Both figures are high because un- stays productive. In Old English alone the prefix formed more than a thousand compounds, and writers still coin new ones freely. Within the last two decades, unfriend, unfollow and unsubscribe all entered general dictionaries. Since writers attach un- to new adjectives every year, no word finder ever reports a final total.
Words That Start With Un For Kids
Younger learners grasp the prefix fastest in pairs, with the base word taught beside the un- word.
- Unbox: to take something out of its box.
- Uncle: your mother’s or father’s brother.
- Uncover: to take the lid or cloth off.
- Undo: to reverse what you just did.
- Unfair: not the same rule for everyone.
- Unfold: to open something folded flat.
- Unhappy: not happy.
- Unkind: not kind to another person.
- Unlock: to open a lock with a key.
- Unpack: to take everything out of a bag.
- Unplug: to pull a plug out of a socket.
- Unsafe: not safe to touch or climb.
- Untidy: not tidy or put away.
- Untie: to loosen a knot or a lace.
- Unzip: to open a zip.
FAQs
Words that start with un are called prefixed words, and the two letters at the front are the prefix un-. Grammar books name two prefixes with this spelling: the negative un-, which attaches to adjectives and nouns, and the reversative un-, which attaches to verbs. Words such as uncle and unit are not prefixed at all, since no base word remains once you remove the un.
The Official Scrabble Dictionary records 4,028 words beginning with un, from two letters to fifteen. Broader word finders that accept general dictionary forms return around 9,489. Neither figure is final, because un- remains productive and writers keep forming new words with it.
Words with the prefix un- form two groups, set apart by what the prefix does. Negative ones such as unfair, unhappy, unkind, unclear and unsafe negate the adjective they attach to. Reversative ones such as untie, unlock, unpack, unfold and unplug reverse the verb they attach to.
Thirty-eight five-letter words begin with un, and these are the most common ones: untie, until, unite, under, unity, unfit, uncle, union, unzip and unset. For Wordle, untie and under are the better guesses, since they contain more common letters.
Positive un- words negate a bad quality rather than a good one, which is how the prefix produces praise. Unique, united, unbeaten, unbiased, undaunted, unselfish, unshakable, unstoppable, unafraid and unflappable all describe someone favourably.
Short un- words run from three to five letters. At three letters you have only uni and uns. The four-letter ones worth knowing are undo, unit, unto, unai and unau, while the five-letter ones are unfit, unfix, unite, unity and unzip.
Words ending in -able show that an action cannot be done. Common ones are unbreakable, unbearable, unavoidable, unbelievable, uncomfortable, undeniable, unforgettable, unreliable, unsuitable and unthinkable.
