Breadcrumb Home > Dictionary > Index L lassie: Meaning and Definition of Find definitions for: las•sie Pronunciation: (las'ē), [key] — n. a young girl; lass. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: lassie (Thesaurus) Lassen Volcanic National Park lassitude ✖ Related Content Daily Word Quiz: umbrage Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language