Un-

[приставка, первая часть сложных слов] 1) не- (придаёт противоположное значение) Например: to undo — уничтожать, отменять сделанное; возвращать к прежнему положению вещей unable — неспособный unappreciation — неблагодарность 2) раз- (глаголам, образованным от существительных, придает обыкновенно значение: "лишать", "освобождать от"; "удалять", "извлекать") Например: to uncap — снимать шляпу to uncart — разгружать тележку 3) усиливает отрицательное значение глагола Например: to unloose — ослаблять

Большой англо-русский словарь

Un-

I. prefix Etymology: Middle English, from Old English; akin to Old High German un- un-, Latin in-, Greek a-, an-, Old English ne not — more at no 1. not; in-, non- — in adjectives formed from adjectives Example: unambitious Example: unskilled or participles Example: undressed, in nouns formed from nouns Example: unavailability, and rarely in verbs formed from verbs Example: unbe — sometimes in words that have a meaning that merely negates that of the base word and are thereby distinguished from words that prefix in- or a variant of it (as im-) to the same base word and have a meaning positively opposite to that of the base word Example: unartistic Example: unmoral 2. opposite of; contrary to — in adjectives formed from adjectives Example: unconstitutional Example: ungraceful Example: unmannered or participles Example: unbelieving and in nouns formed from nouns Example: unrest II. prefix Etymology: Middle English, from Old English un-, on-, alteration of and- against — more at ante- 1. do the opposite of; reverse (a specified action); de- 1a, dis- 1a — in verbs formed from verbs Example: unbend Example: undress Example: unfold 2. a. deprive of; remove (a specified thing) from; remove — in verbs formed from nouns Example: unfrock Example: unsex b. release from; free from — in verbs formed from nouns Example: unhand c. remove from; extract from; bring out of — in verbs formed from nouns Example: unbosom d. cause to cease to be — in verbs formed from nouns Example: unman 3. completely Example: unloose

Merriam-Webster's Collegiate Dictionary