un- (1) — ONAD

un-1 /ən, ən

▸ prefix

1 (added to adjectives, participles, and their derivatives) denoting the absence of a quality or state; not:

unabashed

unacademic

unrepeatable.

▪ the reverse of (usually with an implication of approval or disapproval, or with another special connotation):

unselfish

unprepossessing

unworldly.

2 (added to nouns) a lack of:

unrest

untruth.

– ORIGIN Old English , of Germanic origin; from an Indo-European root shared by Latin in- and Greek a-.

The prefixes un- and non- both mean ‘lacking’ or ‘not,’ but there is a distinction in terms of perspective. The prefix un- tends to be stronger and less neutral than non-. Consider, for example, the differences between unacademic and nonacademic, as in his language was refreshingly unacademic; a nonacademic life suits him.