un- Meaning, Definition & Usage

Un-
Etymology
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-.
Definitions
  1. 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. ✍ Compounds of this prefix are given in full in their proper order in the Vocabulary.
Un-
Etymology
OE. & AS. un-; akin to OFries. un-, D. on-, OS., OHG., & G. un-, Icel. &omac;-, &umac;-, Sw. o-, Dan. u-, W. an-, L. in-, Gr. , , Skr. an-, a-. *193. Cf. A- not In- not, No, adv.
Definitions
  1. 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. I. Un- is prefixed to adjectives, or to words used adjectively. Specifically: -- (a) To adjectives, to denote the absence of the quality designated by the adjective; as, -- Unwitty Unruly uncharismatic unfamous unfastidious unenvious ---- and the like. (b) 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; as, - Unabolishable Unabsolvable Unabsurd Unabundant Unaccordant Unadoptable Unadventurous Unaffable Unaffectionate Unafraid Unalliable Unallowablew Unalterable Unambiguous Unambitious Unamendable Un-American Unamusive Unangular Unanxious Unapocryphal Unapostolic &colbreak; Unapparent Unappeasable Unapplausive Unappreciable Unapprehensible Unapprehensive Unapproachable Unartificial Unartistic Unassailable Unattainable Unattentive Unauthentic Unavailable Unbailable Unbearable Unbeautiful Unbeliefful Unbelievable Unbeneficial Unbenevolent Unblamable &colbreak; Unblemishable Unblissful Unboastful Unbold Unbookish Unbounteous Unbribable Unbrotherly Unburdensome Unbusinesslike Unbusy Uncandid Uncanonical Uncaptious Uncareful Uncelestial Unceremonious Unchallengeable Unchangeable Unchary Unchastisable Uncheerful ---- and the like. (c) 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. The above classes of words are unlimited in extent, and such compounds may be formed by any writer or speaker at will from almost all the adjectives or participles in the language, excepting those which have a recognized and usual negative correspondent with the prefix -in. No attempt will be made, therefore, to define them all in this Dictionary; many will be omitted from its Vocabulary which are negations of the simple word, and are readily explained by prefixing a not to the latter. Derivatives of these words in -ly and -ness will also, for the most part, be omitted for the same or similar reasons. There will be inserted as separate articles with definitions, the following: --
  2. 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.
  3. 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.
  4. 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. II. 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. ✍ Compounds of this last class are given in full in their proper order in the Vocabulary.

Webster 1913