Un-

Un- Un- [OE. un-, on-, the unaccented form of the accented prefix and- (cf. {Answer}); akin to D. ont-, G. ent-, OHG. int-, Goth. and-. See {Anti-}.] An inseparable verbal prefix or particle. It is prefixed: (a) To verbs to express the contrary, and not the simple negative, of the action of the verb to which it is prefixed; as in uncoil, undo, unfold. (b) To nouns to form verbs expressing privation of the thing, quality, or state expressed by the noun, or separation from it; as in unchild, unsex. Sometimes particles and participial adjectives formed with this prefix coincide in form with compounds of the negative prefix un- (see 2d {Un-}); as in undone (from undo), meaning unfastened, ruined; and undone (from 2d un- and done) meaning not done, not finished. Un- is sometimes used with an intensive force merely; as in unloose. [1913 Webster]

Note: Compounds of this prefix are given in full in their proper order in the Vocabulary. [1913 Webster]