Merriam-Webster's Dictionary and Thesaurus - Merriam-Webster [1477]
un·nec·es·sar·i·ly adverb 1 : not by necessity
2 : to an unnecessary degree <~ harsh>
un·nerve verb 1 : to deprive of courage, strength, or steadiness
2 : to cause to become nervous
Synonyms
demoralize, undo, unman; also debilitate, enervate, enfeeble, weaken; prostrate, sap, soften, tire, waste; frighten, scare, terrify, terrorize; daunt, discourage, dishearten, dismay, dispirit; craze, derange, madden, unhinge; discompose, disquiet, disturb, faze, perturb, unsettle, upset
Antonyms
nerve
daunt, demoralize, discourage, dishearten, dismay, dispirit, unman—more at DISCOURAGE
un·nil·hex·i·um noun [ORIGIN: NL, fr. unnil- (fr. L unus one + nil zero) + Gk hex six + NL -ium]
: the chemical element of atomic number 106
un·nil·pen·ti·um noun : the chemical element of atomic number 105
un·nil·qua·di·um noun : the chemical element of atomic number 104
un·num·bered adjective 1 : not numbered or counted
2 : too many to be numbered : INNUMERABLE
Synonyms
countless, innumerable, numberless, uncountable, untold—more at COUNTLESS
un·ob·struct·ed adjective : not obstructed or hindered
Synonyms
clear, free, open—more at OPEN
un·ob·tain·able adjective : not obtainable
Synonyms
inaccessible, inconvenient, unapproachable, unattainable, unavailable, unreachable, untouchable—more at INACCESSIBLE
un·ob·tru·sive adjective : not obtrusive or forward : INCONSPICUOUS
— un·ob·tru·sive·ly adverb
un·oc·cu·pied adjective 1 : not busy : UNEMPLOYED
2 : not occupied : EMPTY, VACANT
un·or·ga·nized adjective 1 : not formed or brought into an integrated or ordered whole
2 : not organized into unions <~ labor>
un·orig·i·nal adjective : not original
Synonyms
imitative, mimic, slavish—more at IMITATIVE
un·or·tho·dox adjective : not orthodox : not in accord with approved, standardized, or conventional doctrine, method, thought, custom, or opinion
Synonyms
broad-minded, liberal, nonorthodox, nontraditional, open-minded, progressive, radical, unconventional—more at LIBERAL
informal, irregular, unceremonious, unconventional—more at INFORMAL
un·pack verb 1 : to separate and remove things packed
2 : to open and remove the contents of
un·paid adjective 1 : not paid : serving without pay
2 a : not presented as payment
b : not cleared by payment
3 : not paying a salary
Synonyms
outstanding, overdue, payable, unsettled—more at OUTSTANDING
un·paint·ed adjective : not painted : not having a coat of paint
Synonyms
colorless, uncolored, white—more at COLORLESS
un·pal·at·able adjective 1 : not palatable : DISTASTEFUL
2 : not pleasant : not amiable or agreeable
un·par·al·leled adjective 1 : having no parallel
2 : having no equal or match
Synonyms
incomparable, inimitable, matchless, nonpareil, only, peerless, unequaled, unmatched, unrivaled, unsurpassed—more at ONLY
un·par·don·able adjective : not worthy of pardon
Synonyms
indefensible, inexcusable, unforgivable, unjustifiable, unwarrantable—more at INEXCUSABLE
un·par·lia·men·ta·ry adjective : contrary to parliamentary practice
un·peg verb 1 : to remove a peg from
2 : to unfasten by or as if by removing a peg
un·per·son noun : a person who usu. for political or ideological reasons is removed from recognition or consideration
un·per·turbed adjective : not perturbed : unaffected by worry, interruption, disturbance, or disarrangement
Synonyms
calm, collected, composed, cool, placid, self-possessed, serene, tranquil, undisturbed, unshaken, untroubled, unworried—more at CALM
un·pile verb : to take or disentangle from a pile
un·pin verb : to remove a pin from : UNFASTEN
un·planned adjective 1 : not planned
2 : not expected
Synonyms
[1] ad-lib, extemporaneous, impromptu, offhand, snap, unpremeditated, unprepared, unrehearsed—more at EXTEMPORANEOUS
[2] accidental, casual, chance, fluky, fortuitous, incidental, unintended, unintentional, unpremeditated, unwitting—more at ACCIDENTAL
un·pleas·ant adjective : not pleasant : DISAGREEABLE