Un word meaning and definition

[noun] an organization of independent states to promote international peace and security

\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. Note: Compounds of this prefix are given in full in their proper order in the Vocabulary.
\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; as,
(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,

Morse code: ..- -.