/ Dictionary / Index L least weasel: Meaning and Definition of Find definitions for: least' wea'sel Pronunciation: [key] a weasel, Mustela nivalis, of northern regions, that grows to a length of about 6 in. (15 cm). Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. leastways leastwise 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