issitudes [vicissitudes = sudden or unexpected changes]

unforgivable tragedy

unfounded conjecture

unfulfilled longing

ungainly figure

ungarnished reality

ungenerously resolved

ungenial temperament

ungovernable vehemence

ungracious temper

ungrudging tribute

unguessed riches

unhallowed threshold

unhampered expression

unhappy predecessor

unheeded beauties

unheroic measure

unhesitating faith

unhindered flight

unholy triumph

uniform blending

unimaginable bitterness

unimpassioned dignity

unimpeachable sentiment

unimpeded activity

uninstructed critic

uninterrupted process

unique personality

universal reprobation
[reprobation = condemned to hell; severe disapproval]

unjust depreciation

unknown appellations [appellation = name, title, or designation]

unlettered laborer

unlikely contingency

unlimited opulence

unlucky dissembler

unmanly timidity

unmastered possibility.

unmeaning farce

unmeasured hostility

unmellowed dawn

unmelodious echoes

unmerciful plundering

unmingled consent

unmistakably fabulous

unmitigated gloom

unmixed astonishment

unmodified passion

unmurmuring sea

unnecessary platitudes

unnumbered thousands

unobtrusive deference

unostentatious display

unpalatable truth

unparalleled atrocities

unpardonable error

unphilosophical dreamer

unpleasant excrescence [excrescence = abnormal enlargement]

unprecedented advance

unprejudiced intelligence

unpretentious character

unprincipled violence

unprofitable craft

unpurchasable luxury

unqualified submission

unquenchable tenderness

unquestionable genius

unquestioning fate

unreasonable pretense

unreasoning distrust

unredeemable forfeit

unrefreshing sameness

unrelaxing emphasis

unrelenting spirit

unremembered winter

unremitting toil

unrepining sadness

unreproved admiration

unrequited love

unresentful disposition

unreserved assent

unresisted authority

unresolved exceptions

unresponsive gloom

unresting speed

unrestrained anger

unrestricted ease

unrivaled distinction

unruffled concord

unsatisfied yearning

unscrupulous adventurer

unseasonable apology

unseemly mirth

unselfish fidelity

unsettled trait

unshakable foundation

unshrinking determination

unslackened volubility [volubility = ready flow of speech; flue