Un-

From Middle English un-, from Old English un- ("un-"), from Proto-Germanic *un- ("un-"), from Proto-Indo-European *n̥- ("un-, not"). Cognate with Scots un-, on- ("un-"), North Frisian ün- ("un-"), Saterland Frisian uun- ("un-"), West Frisian ûn-, on- (""), Dutch on- ("un-"), Low German un-, on- ("un-"), German un- ("un-"), Danish u- ("un-"), Swedish o- ("un-"), Norwegian u- ("un-"), Icelandic ó- ("un-"). Related also to Latin in-, Ancient Greek ἀ- (modern Greek α-) and Sanskrit अ-.

Full definition of un-

Prefix

1. (added to adjectives or past participles) notunannounced — “not being announced”uneducated — “not educated”unattractive — “not attractive”unconstitutional — “not constitutional”
2. (added to nouns) absent, lacking, notungrace ("lack of grace, gracelessness")unrest ("a lack of rest (peace); war")unhope ("despair")unfriend ("enemy")unrepair ("")unluck ("misfortune")unnova

Usage notes

Some words formed in this way may also have counterparts using in- or non-.

Derived terms

From Middle English on-, from Old English ond-, and- ("against, facing, toward; in return, back, without"), from Proto-Germanic *anda-, *andi- ("against"), from Proto-Indo-European *anta, *anti, *h₂ént-i ("across, forth, forward, ahead"), from Proto-Indo-European *h₂ént- ("end, limit, forehead"). More at and-.

Prefix

1. (added to verbs and nouns to form verbs) reverse, oppositeto undress — “to take one's clothes off”to unwind — “to reverse a winding”to unlock — “to undo the locking of”
• 1996, Diane Warren (writer), Toni Braxton (singer), “Un-Break My Heart”, Secrets, LaFaceUn-cry these tears I cried so many nights
  Un-break my heart
2. release, free, remove, extract.to uncage — “to release from a cage”to untangle — “to remove the tangling of”

Usage notes

Only certain words can take un- to form a new word with the opposite meaning. In particular, verbs that describe an irreversible action produce words often considered nonsense, e.g. unkill, unspend, unlose, unring. These words may nevertheless be in occasional use for humorous or other effect.

Synonyms

• (opposite) anti-, in-, non-
• (release) de-, dis-

From Latin Å«nus.

Prefix

1. Used to form temporary names of elements (such as ununbium) whose existence has been predicted, and have not yet been given a systematic name.

Synonyms

• -un-