/ Dictionary / Index L lessen: Meaning and Definition of Find definitions for: less•en Pronunciation: (les'un), [key] — v.i. to become less. —v.t. to make less; reduce. to represent as less; depreciate; disparage. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: lessen (Thesaurus) lessee Lesseps Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language