unforgiving, a. [implacable], irremissive, [relentless].
unfortunate, a. [unlucky], [unsuccessful], [disastrous], ill-starred, ill-fated.
unfounded, a. [baseless], [groundless].
unfriendliness, n. [enmity], inimicalness, [hostility], [disfavor], [antipathy], disaffection, [alienation], [estrangement], unfriendship.
unfriendly, a. [hostile], ill-disposed, inimical, malign, unamicable, disaffected, alienated, [estranged], [antagonistic], [unfavorable], adverse.
unfruitful, a. [unproductive], [effete], unprolific, infertile, acarpous.
ungainly, a. [awkward], [gawky], [ungraceful], [lumbering], [loutish], wooden, [uncouth].
ungenerous, a. [illiberal], [narrow], [sordid], [uncharitable], [stingy].
unglue, v. deglutinate.
ungodly, a. [godless], impious, irreverent, [profane], [unrighteous].