- (adv.) To past particles or to adjectives formed after the analogy of past particles, to indicate the absence of the condition or state expressed by them.
- 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.
- (adv.) Those which have acquired an opposed or contrary, instead of a merely negative, meaning; as, unfriendly, ungraceful, unpalatable, unquiet, and the like; or else an intensive sense more than a prefixed not would express; as, unending, unparalleled, undisciplined, undoubted, unsafe, and the like.
- (adv.) Those which have the value of independent words, inasmuch as the simple words are either not used at all or are rarely or at least much less frequently, used; as, unavoidable, unconscionable, undeniable, unspeakable, unprecedented, unruly, and the like; or inasmuch as they are used in a different sense from the usual meaning of the primitive or especially in one of the significations of the latter; as, unaccountable, unalloyed, unbelieving, unpretending, unreserved, and the like; or inasmuch as they are so frequently and familiarly used that they are hardly felt to be of negative origin; as, uncertain, uneven, and the like.
- (adv.) Those which are anomalous, provincial, or, for some other reason, not desirable to be used, and are so indicated; as, unpure for impure, unsatisfaction for dissatisfaction, unexpressible for inexpressible, and the like.
- (adv.) Un- is prefixed to nouns to express the absence of or the contrary of, that which the noun signifies; as, unbelief, unfaith, unhealth, unrest, untruth, and the like.
- (adv.) To adjectives, to denote the absence of the quality designated by the adjective.
- (adv.) An inseparable prefix or particle, signifying not; in-; non-. In- is prefixed mostly to words of Latin origin or else to words formed by Latin suffixes; un- is of much wider application, and is attached at will to almost any adjective or participle used adjectively or adverb, from which it may be desired to form a corresponding negative adjective or adverb, and is also, but less freely, prefixed to nouns. Un- sometimes has merely an intensive force; as in unmerciless, unremorseless.
- (adv.) Un- is prefixed to adjectives or to words used adjectively.
- (adv.) To present particles which come from intransitive verbs or are themselves employed as adjectives, to mark the absence of the activity, disposition or condition implied by the participle; as, - ---- and the like.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). un-. Retrieved September 21, 2026, from http://smartdefine.org/un-/definitions/2076159 |
| Chicago | Webster's. 2011. "un-" http://smartdefine.org/un-/definitions/2076159 (accessed September 21, 2026). |
| Harvard | Webster's 2011, un-, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/un-/definitions/2076159>. |
| MLA | Webster's. "un-" 28 May 2011. Web. 21 September 2026. <http://smartdefine.org/un-/definitions/2076159> |