/ Dictionary / Index L lambda: Meaning and Definition of Find definitions for: lamb•da Pronunciation: (lam'du), [key] — n. the 11th letter of the Greek alphabet (&Lgr;, &lgr;). the consonant sound represented by this letter. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: lambda (Thesaurus) lambaste lambdacism Related Content Daily Word Quiz: cygnet Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language