Not; opposed to. [OE] ♦ Un–¹ is used to express negation, lack, incompleteness or opposition. It is freely attached to adjectives and adverbs, less often to nouns.
See UN–².

Back. [OE un-, on-, and-] ♦ Un–² is used to express reversal of the action of verbs, or to form verbs from nouns indicating removal from the state or quality expressed by the noun, or sometimes to intensify the force of negative verbs. Beginning at the foot of this page will be found a partial list of words which are formed with un–¹ and un–². Other compounds of these prefixes, with strongly positive, specific, or special meanings, will be found in vocabulary place. In the verbs in the list un– gives the sense of reversal: unchain “to loose the chains of.” In the nouns and the adjectives usually it has negative or privative force. Thus, unburdened may be regarded as an adjective meaning “not burdened,” or as a participle of the verb unburden, meaning “relieved of a burden.” In– as a prefix of adjectives expresses in usage more of negation, un– more of mere lack or privation: a child's unartistic speech, a writer's inartistic diction. In general, in– is more confined to words of Latin origin.
Pronunciations may be ascertained by consulting the second element in its vocabulary place.