/ Dictionary / Index L lambda particle: Meaning and Definition of Find definitions for: lamb'da par"ticle Pronunciation: [key] — Physics. Physics. any of a family of neutral baryons with strangeness −1 or charm +1, and isotopic spin 0. The least massive member of the lambda family was the first strange particle to be discovered. Symbol: &Lgr; Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. lambdacism lambdoid 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