/ Dictionary / Index U uptime: Meaning and Definition of Find definitions for: up•time Pronunciation: (up'tīm"), [key] — n. the time during which a machine or piece of equipment, as a computer, is operating or can be operated. the time during which an employee is actually working. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: uptime (Thesaurus) uptilt up-to-date Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language