Un-

Un- Un- [OE. & AS. un-; akin to OFries. un-, D. on-, OS., OHG., & G. un-, Icel. [=o]-, [=u]-, Sw. o-, Dan. u-, W. an-, L. in-, Gr. ?, ?, Skr. an-, a-. [root]193. Cf. {A-} not {In-} not, No, 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. 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; (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; (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;

Note: 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: 1. 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. 2. 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. 3. 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.

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