ultimate adj. being last in a series, process, or progression; fundamental; elemental; eventual¹

ultimately adv. in the end; eventually

unanimous adj. sharing the same opinions or views; being in complete harmony or accord; based on or characterized by complete assent^{2 or agreement}

unauthorized adj. unlicensed; forbidden; unlawful

unbiased adj. impartial^{4; equitable5}

uncertainty^{6 n. doubtfulness}

unconventional adj. not standard; not ordinary

undercut v. to offer at lower prices than the competition; to cut off the under part; to slice the ball from underneath^{7 ; to weaken; to undermine}

underestimate v. to assign too low a value to

underlie^{8 v. to be located under or below; to be the support or basis of; account for; to constitute a prior financial claim over}

underline n. caption^{9 beneath an illustration}

underline v. to emphasize

undermine v.to weaken by wearing away a base or foundation; to weaken, injure, or impair^{10, often by degrees or imperceptibly; sap;}

understatement n. representing something less strongly than what the facts would justify^{11; statement expressing something in a restrained manner}

underway adj. having begun a journey ; initiated^{12; in progress; under construction}

unfair adj. biased^{3; dishonest}

unforeseen adj. not anticipated; not expected

unfortunately adv. regrettably

uniform adj. always the same, as in character or degree; unvarying; conforming to one principle, standard, or rule; consistent; being the same as or consonant^{13 with another or others}

uniform n. a distinctive^{14 outfit15 intended to identify those who wear it as members of a specific group}

unify^{16 v. to join; to cause to become one}

union n. workers' association; federation^{17; amalgamation18; marriage; reproductive coupling; device which fits two pieces together}

unique adj. singular; matchless; rare

uniqueness n. singularity; inpiduality; incomparability

unit n. specific quantity regarded as a standard; combination which acts a whole; piece; furniture; device; apparatus¹⁹

unlessconj. not before; precluding^{20; barring; except; aside from}

unlimited^{21 adj. infinite; boundless22}

unlock v. to open; to free from restraints; to release

unnecessary adj. excessive; redundant^{23; superfluous24}

unsanitary adj. not healthful; not clean

unsatisfactory adj. inadequate^{25; disappointing; not good enough}

unveil v. to reveal; to uncover; to disclose

upcoming adj. about to happen; imminent²⁶

upgrade n. update; installation of a newer version of a program or the replacing of a system component^{27 with a newer component ; hill; acclivity}

upgrade v. to improve; to raise the quality of; to exchange something for another of better quality

upholstery n. materials that are used to cushion and cover furniture ; process of cushioning and covering furniture

upwards^{30 adv. to a higher level; more than; higher than}

urban adj. pertaining^{31 to or characteristic of a city; living in a city; municipal}

urbanize v. to change from rural to urban; to make into a city; to impart urban characteristics

urge v. to force or drive forward or onward^{32; impel33; to entreat34 earnestly and often repeatedly; exhort35; to advocate earnestly the doing, consideration, or approval of; press for; to move or impel to action, effort, or speed; spur}

urgent adj. pressing; compelling; immediate^{36; prompt}

utilization^{37 n. employment; use of; putting to practical use}

utilize^{38 v. to put to practical use; to take advantage of}

utmost adj. being or situated^{39 at the most distant limit or point; farthest; of the highest or greatest degree, amount, or intensity40; most extreme}

utmost n. the greatest possible amount, degree, or extent; the maximum