| ultimately (adverb) in the end; eventually | unable (adjective) not capable |
| unauthorized (adjective) unlicensed; forbidden; unlawful | unbiased (adjective) impartial; equitable |
| uncertain (adjective) doubtful; not reliable; ambiguous | uncertainty (noun) form plural: uncertainties doubtfulness |
| unconventional (adjective) not standard; not ordinary | undercut (noun) form plural: undercuts type of beef tenderloin; type of cavity with a broad base |
| undercut (verb) forms: undercut; undercut; undercutting to offer at lower prices than the competition; to weaken; to undermine | underestimate (verb) forms: underestimated; underestimated; underestimating to assign too low a value to |
| underline (noun) form plural: underlines caption beneath an illustration | underline (verb) forms: underlined; underlined; underlining to emphasize |
| understatement (noun) form plural: understatements representing something less strongly than what the facts would justify | underway (adjective) having begun a journey (especially of a sea vessel); initiated; in progress; under construction |
| unfair (adjective) biased; dishonest | unforeseen (adjective) not anticipated; not expected |
| unfortunately (adverb) regrettably | unify (verb) forms: unified; unified; unifying to join; to cause to become one |
| union (noun) form plural: unions workers' association; federation; amalgamation | unique (adjective) singular; matchless; rare |
| uniqueness (noun) form: no plural singularity; individuality; incomparability | unit (noun) form plural: units specific quantity regarded as a standard; combination which acts a whole; piece |
| unjudged (adjective) objective | unless (conjunction) not before; precluding; barring; except; aside from |
| unlimited (adjective) infinite; boundless | unlock (verb) forms: unlocked; unlocked; unlocking to open; to free from restraints; to release |
| unnecessary (adjective) excessive; redundant; superfluous | unsanitary (adjective) not healthful; not clean |
| unsatisfactory (adjective) inadequate; disappointing; not good enough | until (conjunction) up to the time which |
| until (preposition) up to | unveil (verb) forms: unveiled; unveiled; unveiling to reveal; to uncover; to disclose |
| upcoming (adjective) about to happen; imminent | update (noun) form plural: updates more current version of something |
| update (verb) forms: updated; updated; updating to modernize; to make current | upgrade (noun) form plural: upgrades the process of installing a newer and more powerful version of a software package or a piece of hardware |
| upgrade (verb) forms: upgraded; upgraded; upgrading to improve; to raise the quality of | upholstery (noun) form plural: upholsteries materials that are used to cushion and cover furniture (i.e. fabric, lining, padding, etc.) |
| upon (preposition) on; atop | upwards (adverb) to a higher level; more than; higher than |
| urban (adjective) pertaining to a city; municipal | urbanize (verb) forms: urbanized; urbanized; urbanizing to make into a city |
| urgent (adjective) pressing; compelling; immediate; prompt | use (noun) form plural: uses function; utilization; benefit; advantage; consumption |
| use (verb) forms: used; used; using to practice; to employ; to exploit; to treat; to consume | useful (adjective) functional; practical; applicable |
| useless (adjective) not functional; not practical | usual (adjective) common; regular; ordinary |
| usually (adverb) commonly; generally; regularly | utilization (noun) form plural: utilizations the proportion of available time that an item of equipment is operating |
| utilize (verb) forms: utilized; utilized; utilizing to put to practical use; to take advantage of |