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 unbend 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