/ Dictionary / Index L lookup: Meaning and Definition of Find definitions for: look•up Pronunciation: (look'up"), [key] — n. an act or instance of looking something up, as information in a reference book or an on-line database. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: lookup (Thesaurus) look-through looky Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language