pref.
Pronunciation: ˌ ə n, often ' ə n before ' - stressed syllable
Function: prefix
Etymology: Middle English, from Old English; akin to Old High German un- un-, Latin in-, Greek a-, an-, Old English ne not ― more at NO
1 : not : IN- , NON- ― in adjectives formed from adjectives < un ambitious> < un skilled> or participles < un dressed>, in nouns formed from nouns < un availability>, and rarely in verbs formed from verbs < un be> ― sometimes in words that have a meaning that merely negates that of the base word and are thereby distinguished from words that prefix in- or a variant of it (as im- ) to the same base word and have a meaning positively opposite to that of the base word < un artistic> < un moral>
2 : opposite of : contrary to ― in adjectives formed from adjectives < un constitutional> < un graceful> < un mannered> or participles < un believing> and in nouns formed from nouns < un rest>