1560s, "not argued with," from un- (1) "not" + past participle of dispute (v.). Meaning "not called into question" is attested from 1620s.ETD undisputed (adj.).2

undistinguished (adj.)

1590s, "not kept distinct," from un- (1) "not" + distinguished. Meaning "not elevated above others" is attested from c. 1600.ETD undistinguished (adj.).2

undistinguishable

1580s, from un- (1) "not" + distinguishable.ETD undistinguishable.2

undisturbed (adj.)

c. 1600, from un- (1) "not" + disturbed.ETD undisturbed (adj.).2

undivided (adj.)

early 15c., from un- (1) "not" + past participle of divide (v.).ETD undivided (adj.).2

undivulged (adj.)

c. 1600, from un- (1) "not" + past participle of divulge (v.).ETD undivulged (adj.).2

undo (v.)

Old English undon "to unfasten and open" (a window or door), "to unfasten by releasing from a fixed position; to cancel, discharge, abrogate, reverse what has been done, put back in a former condition; bring to ruin, destroy," from un- (2) "opposite of" + do (v.). Related: Undone; undoing.ETD undo (v.).2

undocumented (adj.)

1883, from un- (1) "not" + past participle of document (v.).ETD undocumented (adj.).2

undomesticated (adj.)

1787, of women, "unsuited to home life," 1813, of animals, "not brought under control of humans," from un- (1) "not" + past participle of domesticate (v.). Undomestic "not caring for home life" is recorded from 1754.ETD undomesticated (adj.).2

undone (adj.)

"not accomplished," c. 1300, from un- (1) "not" + done. The same word meaning "destroyed" is recorded from mid-14c., past-participle adjective from undo.ETD undone (adj.).2

undoubted (adj.)

mid-15c., from un- (1) "not" + past participle of doubt (v.). Related: Undoubtedly.ETD undoubted (adj.).2

undoubtable (adj.)

early 15c., from un- (1) "not" + doubt (v.) + -able. Related: Undoubtably.ETD undoubtable (adj.).2

undreamed (adj.)

1610s, from un- (1) "not" + past participle of dream (v.).ETD undreamed (adj.).2

undress (v.)

1590s, "to shed one's clothing," from un- (2) "opposite of" + dress (v.). Transitive sense of "to strip off (someone's) clothing" is recorded from 1610s. Related: Undressed; undressing.ETD undress (v.).2

undressed (adj.)

"naked (or nearly so)," 1610s, past-participle adjective from undress (v.).ETD undressed (adj.).2

undress (n.)

"state of partial or incomplete dress," 1680s, from undress (v.). Meaning "ordinary dress" is from 1748.ETD undress (n.).2

undue (adj.)

late 14c., "not owing or payable; unjustly demanded," also "not appropriate, unseasonable," also "excessive," from un- (1) "not" + past participle of due (v.). Formed on model of Old French indeu, Latin indebitus.ETD undue (adj.).2

undulation (n.)

1640s, from Medieval Latin *undulatio, from Late Latin undulatus "wavy, undulated," from undula "wavelet," diminutive of Latin unda "a wave," from PIE *unda-, nasalized form of root *wed- (1) "water; wet."ETD undulation (n.).2

undulant (adj.)

1830, from Latin undulantem (nominative undulans), from unda "a wave," from PIE *unda-, nasalized form of root *wed- (1) "water; wet."ETD undulant (adj.).2

undulate (v.)

"to move in waves," 1660s, back-formation from undulation. Related: undulated, undulating.ETD undulate (v.).2

unduly (adv.)

late 14c., "without due moderation; improperly, unsuitably;" see undue + -ly (2). From early 15c. as "unjustly, wrongfully."ETD unduly (adv.).2

unearned (adj.)

c. 1200, from un- (1) "not" + past participle of earn (v.). Unearned income is recorded from 1889.ETD unearned (adj.).2

unearth (v.)

"to dig up," mid-15c., from un- (2) "opposite of" + earth (v.) "bury (a corpse) in the ground" (c. 1400, from earth (n.)). Related: Unearthed; unearthing.ETD unearth (v.).2

unearthly (adj.)

1610s, "heavenly, sublime," from un- (1) "not" + earthly. Sense of "ghostly, weird" is attested by 1802. Related: Unearthliness.ETD unearthly (adj.).2

uneasy (adj.)

late 13c., "not comforting, causing trouble," from un- (1) "not" + easy (adj.). Meaning "disturbed in mind" is attested from 1670s. Related: Uneasily; uneasiness.ETD uneasy (adj.).2

uneducated (adj.)

1580s, from un- (1) "not" + past participle of educate (v.).ETD uneducated (adj.).2

unelectable (adj.)

also un-electable, 1962, from un- (1) "not" + electable.ETD unelectable (adj.).2

unemancipated (adj.)

1775, from un- (1) "not" + past participle of emancipate (v.).ETD unemancipated (adj.).2

unemotional (adj.)

1819, from un- (1) "not" + emotional (adj.). Related: Unemotionally.ETD unemotional (adj.).2

unemployed (adj.)

1600, "at leisure, not occupied," from un- (1) "not" + past participle of employ (v.). Meaning "temporarily out of work" is from 1660s. There seems not to have been a verb *unemploy, but disemploy was used (1610s). The noun meaning "unemployed persons collectively" is from 1782.ETD unemployed (adj.).2

unemployment (n.)

1887, from un- (1) "not" + employment.ETD unemployment (n.).2

unencumbered (adj.)

1722, from un- (1) "not" + past participle of encumber (v.).ETD unencumbered (adj.).2

unending (adj.)

1660s, from un- (1) "not" + present participle of end (v.).ETD unending (adj.).2

unendurable (adj.)

1620s, from un- (1) "not" + endurable. Related: Unendurably.ETD unendurable (adj.).2

un-English (adj.)

"lacking in qualities regarded as typically English," 1630s, from un- (1) "not" + English (adj.).ETD un-English (adj.).2

unenlightened (adj.)

1660s, "not lit up," from un- (1) "not" + past participle of enlighten (v.). Meaning "not mentally illuminated" is attested from 1650s.ETD unenlightened (adj.).2

unenthusiastic (adj.)

1805, from un- (1) "not" + enthusiastic (adj.). Related: Unenthusiastically.ETD unenthusiastic (adj.).2

unenviable (adj.)

1640s, from un- (1) "not" + enviable (adj.). Related: Unenviably.ETD unenviable (adj.).2

unequal (adj.)

1530s, "unjust, unfair," from un- (1) "not" + equal (adj.). Meaning "not the same in amount, size, quality, etc." is recorded from 1560s (inequal in this sense is from late 14c.). Sense of "inadequate, insufficient" (to some task) is attested from 1690s. Related: Unequally.ETD unequal (adj.).2

unequivocal (adj.)

1784, from un- (1) "not" + equivocal. Related: Unequivocally.ETD unequivocal (adj.).2

unerring (adj.)

1640s (implied in unerringly), from un- (1) "not" + verbal noun from err. Related: Unerringly.ETD unerring (adj.).2

UNESCO

acronym from United Nations Educational, Scientific and Cultural Organization, which was created in 1945.ETD UNESCO.2

unethical (adj.)

1871, from un- (1) "not" + ethical. Related: Unethically.ETD unethical (adj.).2

uneventful (adj.)

1800, from un- (1) "not" + eventful. Related: Uneventfully.ETD uneventful (adj.).2

uneven (adj.)

Old English unefen "unequal, unlike, anomalous, irregular," from un- (1) "not" + even (adj.). Similar formation in Old Frisian oniovn, Middle Dutch oneven, Old High German uneban, German uneben, Old Norse ujafn. Meaning "broken, rugged" (in reference to terrain, etc.) is recorded from late 13c. Related: Unevenly; unevenness.ETD uneven (adj.).2

unevitable (adj.)

from un- (1) "not" + evitable. The usual word is inevitable. Related: Unevitably.ETD unevitable (adj.).2

unexamined (adj.)

late 15c., from un- (1) "not" + past participle of examine (v.).ETD unexamined (adj.).2

unexceptional (adj.)

from un- (1) "not" + exceptional (adj.).ETD unexceptional (adj.).2

unexceptionable (adj.)

1660s, from un- (1) "not" + exceptionable.ETD unexceptionable (adj.).2

unexcusable (adj.)

late 14c., from un- (1) "not" + excusable. The usual word is inexcusable. Related: Unexcusably.ETD unexcusable (adj.).2

unexpected (adj.)

1580s, from un- (1) "not" + past participle of expect (v.). Related: Unexpectedly.ETD unexpected (adj.).2

unexperienced (adj.)

1560s, from un- (1) "not" + past participle of experience (v.).ETD unexperienced (adj.).2

unexplained (adj.)

1721, from un- (1) "not" + past participle of explain (v.).ETD unexplained (adj.).2

unexplainable (adj.)

1711, from un- (1) "not" + explain + -able. Related: Unexplainably.ETD unexplainable (adj.).2

unexplored (adj.)

1690s, from un- (1) "not" + past participle of explore (v.).ETD unexplored (adj.).2

unexpurgated (adj.)

1882, from un- (1) "not" + past participle of expurgate (v.).ETD unexpurgated (adj.).2

unfading (adj.)

from un- (1) "not" + past participle of fade (v.).ETD unfading (adj.).2

unfailing (adj.)

late 14c., "never coming to an end, unceasing, everlasting, inexhaustible," from un- (1) "not" + present participle of fail (v.). Related: Unfailingly.ETD unfailing (adj.).2

unfairness (n.)

Old English unfægernes "ugliness, disfigurement;" see unfair + -ness.ETD unfairness (n.).2

unfair (adj.)

Old English unfægr "unlovely, not beautiful, deformed, hideous, unlovable," from un- (1) "not" + fair (adj.). Similar formation in Old Norse ufagr, Gothic unfagrs. The meaning "wicked, evil, bad" is recorded from c. 1300. The sense of "not equitable, unjust" is first attested 1713. Related: Unfairly.ETD unfair (adj.).2

unfaithful (adj.)

mid-14c., "acting falsely," from un- (1) "not" + faithful. In Middle English it had also a sense of "infidel, unbelieving, irreligious" (late 14c.). The meaning "not faithful in marriage" is attested from 1828. Related: Unfaithfully; unfaithfulness.ETD unfaithful (adj.).2

unfaltering (adj.)

1660s, from un- (1) "not" + present participle of falter (v.). Related: Unfalteringly.ETD unfaltering (adj.).2

unfamous (adj.)

late 14c., "not well known, obscure," from un- (1) "not" + famous (adj.). Also from late 14c. as "notably bad," a sense now in infamous.ETD unfamous (adj.).2

unfamiliar (adj.)

1590s, from un- (1) "not" + familiar (adj.). Related: Unfamiliarly; unfamiliarity.ETD unfamiliar (adj.).2

unfashionable (adj.)

1560s, "incapable of being shaped," from un- (1) "not" + fashionable. Meaning "not in accordance with prevailing fashion" is attested from 1640s. Related: Unfashionably.ETD unfashionable (adj.).2

unfasten (v.)

early 13c., from un- (2) "opposite of" + fasten. Old English had unfæstnian "to unfasten." Related: Unfastened; unfastening.ETD unfasten (v.).2

unfathomed (adj.)

1620s, from un- (1) "not" + past participle of fathom (v.).ETD unfathomed (adj.).2

unfathomable (adj.)

1610s, originally in the figurative sense, of feelings, conditions, etc., "too deep to be comprehended," from un- (1) "not" + fathomable. Literal sense of "too deep to be measured" is attested from 1670s. Related: Unfathomably.ETD unfathomable (adj.).2

unfavorable (adj.)

also unfavourable, mid-15c. (implied in unfavorably), from un- (1) "not" + favorable (adj.).ETD unfavorable (adj.).2

unfazed (adj.)

1933, American English, from un- (1) "not" + past participle of faze (v.).ETD unfazed (adj.).2

unfeasible (adj.)

1520s, from un- (1) "not" + feasible.ETD unfeasible (adj.).2

unfeeling (adj.)

late Old English had unfelende, "having no sensation." Middle English had a verb unfeel "be insensible, fail to feel" (early 14c.) as well as unfeelingness "insensibility, loss of sensation," and unfeelingly "without understanding or direct knowledge" (late 14c.), and a verbal noun unfeeling "loss of sensation, lack of feeling." However the word in its main modern meaning "devoid of kindly or tender feelings" is from 1590s, from un- (1) "not" + past participle of feel (v.). Related: Unfeelingly.ETD unfeeling (adj.).2

unfeigned (adj.)

late 14c., "sincere, genuine, true, real," from un- (1) "not" + past participle of feign (v.).ETD unfeigned (adj.).2

unfelt (adj.)

1580s, from un- (1) "not" + past participle of feel (v.).ETD unfelt (adj.).2

unfetter (v.)

mid-14c., from un- (2) "opposite of" + fetter (v.). The figurative sense is recorded from late 14c. Related: Unfettered; unfettering.ETD unfetter (v.).2

unfinished (adj.)

1550s, from un- (1) "not" + past participle of finish (v.).ETD unfinished (adj.).2

unfit (v.)

"to render unfit," 1610s, from unfit (adj.), or else from un- (2) "reverse of" + fit (v.). Related: Unfitted; unfitting.ETD unfit (v.).2

unfit (adj.)

1540s, "not suitable" (in reference to things), from un- (1) "not" + fit (adj.). Related: Unfitness. In reference to persons or human qualities, attested from 1550s.ETD unfit (adj.).2

unflagging (adj.)

1715, from un- (1) "not" + present participle of flag (v.). Related: Unflaggingly.ETD unflagging (adj.).2

unflappable (adj.)

1958, from un- (1) "not" + flap (v.) + -able. Originally used in reference to Harold Macmillan, British P.M. 1957-63.ETD unflappable (adj.).2

unflattering (adj.)

1580s, from un- (1) "not" + gerundive of flatter. Related: Unflatteringly.ETD unflattering (adj.).2

unfledged (adj.)

c. 1600, of persons, "immature, not experienced," from un- (1) "not" + past participle of fledge (v.). Literal sense of "not yet covered in feathers" is recorded from 1610s.ETD unfledged (adj.).2

unflinching (adj.)

1728, from un- (1) "not" + present-participle adjective of flinch (v.). Related: Unflinchingly.ETD unflinching (adj.).2

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.ETD unfold (v.).2

unforced (adj.)

1590s, from un- (1) "not" + past participle of force (v.).ETD unforced (adj.).2

unforeseeable (adj.)

1670s, from un- (1) "not" + foreseeable (see foresee). Related: Unforeseeably.ETD unforeseeable (adj.).2

unforeseen (adj.)

late 14c., from un- (1) "not" + past participle of foresee. Similar formation in Middle Dutch onvoresien, Dutch onvoorzien, Middle High German unvorsen.ETD unforeseen (adj.).2

unforgettable (adj.)

1806, from un- (1) "not" + forgettable. Related: Unforgettably.ETD unforgettable (adj.).2

unforgiving (adj.)

1713, from un- (1) "not" + present-participle adjective from forgive. Old English had unforgifende.ETD unforgiving (adj.).2

unforgivable (adj.)

1540s, from un- (1) "not" + forgivable. In early use, especially with reference to the sin described in Matthew xii.31. Related: Unforgivably.ETD unforgivable (adj.).2

unforgiven (adj.)

early 15c., from un- (1) "not" + past-participle adjective from forgive (v.). Old English had unforgifen.ETD unforgiven (adj.).2

unforgotten (adj.)

1670s, from un- (1) "not" + forgotten. Similar formation in German unvergessen.ETD unforgotten (adj.).2

unformed (adj.)

early 14c., from un- (1) "not" + past-participle adjective from form (v.).ETD unformed (adj.).2

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.ETD unfortunately (adv.).2

unfortunate (adj.)

mid-15c., "unlucky," from un- (1) "not" + fortunate (adj.). Infortunate in same sense is older. 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.ETD unfortunate (adj.).2

unfortune (n.)

"misfortune, bad luck," early 15c., from un- (1) "not" + fortune (n.).ETD unfortune (n.).2

unfounded (adj.)

1640s, "having no foundation or basis," from un- (1) "not" + past participle of found (v.1).ETD unfounded (adj.).2

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.ETD unfree (adj.).2

unfrequented (adj.)

1580s, from un- (1) "not" + past participle of frequent (v.).ETD unfrequented (adj.).2

underage (adj.) — undisguised (adj.)

unfriend (v.) — Union Jack