- unflinching (adj.)
[unflinching 词源字典] - 1728, from un- (1) "not" + present participle adjective of flinch (v.). Related: Unflinchingly.[unflinching etymology, unflinching origin, 英语词源]
- unfold (v.)
- Old English unfealdan, "to open or unwrap the folds of," also figuratively, "to disclose, reveal, explain," from un- (2) "opposite of" + fold (v.). Similar formation in Middle Dutch ontvouden, German entfalten. Intransitive sense is attested from late 14c. Related: Unfolded; unfolding.
- unforced (adj.)
- 1590s, from un- (1) "not" + past participle of force (v.).
- unforeseeable (adj.)
- 1670s, from un- (1) "not" + foreseeable (see foresee). Related: Unforeseeably.
- unforeseen (adj.)
- late 14c., from un- (1) "not" + past participle of foresee. Similar formation in Middle Dutch onvoresien, Dutch onvoorzien, Middle High German unvorsen.
- unforgettable (adj.)
- 1806, from un- (1) "not" + forgettable. Related: Unforgettably.
- unforgivable (adj.)
- 1540s, from un- (1) "not" + forgivable. In early use, especially with reference to the sin described in Matt. xii:31. Related: Unforgivably.
- unforgiven (adj.)
- early 15c., from un- (1) "not" + past participle adjective from forgive (v.). Old English had unforgifen.
- unforgiving (adj.)
- 1713, from un- (1) "not" + present participle adjective from forgive. Old English had unforgifende.
- unforgotten (adj.)
- 1670s, from un- (1) "not" + forgotten. Similar formation in German unvergessen.
- unformed (adj.)
- early 14c., from un- (1) "not" + past participle adjective from form (v.).
- unfortunate (adj.)
- mid-15c., "unlucky," from un- (1) "not" + fortunate (adj.). Infortunate in same sense is from late 14c. (along with a verb infortune "to render unhappy"). In late 18c.-early 19c., unfortunate woman was a polite way to say "prostitute." The noun meaning "one who is not fortunate" is recorded from 1630s.
- unfortunately (adv.)
- 1540s, "in an unfortunate manner, by ill-fortune," from unfortunate + -ly (2). The original meaning is now rare; the main modern sense of "sad to say, unhappily, unluckily," in parenthetical use, is recorded from 1770s.
- unfortune (n.)
- "misfortune, bad luck," early 15c., from un- (1) "not" + fortune (n.).
- unfounded (adj.)
- 1640s, "having no foundation or basis," from un- (1) "not" + past participle of found (v.1).
- unfree (adj.)
- c. 1300, from un- (1) "not" + free (adj.). Similar formation in Middle Dutch onvri, Old High German unfri, German unfrei, Middle Danish ufri.
- unfrequented (adj.)
- 1580s, from un- (1) "not" + past participle of frequent (v.).
- unfriend (v.)
- in the Facebook sense, attested from November 2007, from un- (1) "not" + friend (v.). Unfriended is at least as old as Shakespeare in the sense "friendless." A noun unfriend "enemy" is recorded from late 13c., chiefly in Scottish, and was still in use in the 19th century.
- unfriendly (adj.)
- early 15c., "not characteristic of friends, hostile, inimical," from un- (1) "not" + friendly. Similar formation in Middle Dutch onvriendelijc, Middle High German unvriuntlich, German unfreundlich. Old English had unferondlice "unkindly." Related: Unfriendliness.
- unfruitful (adj.)
- late 14c., "barren," from un- (1) "not" + fruitful. Originally literal; figurative sense is attested from c. 1400. Related: Unfruitfully; unfruitfulness.
