/ Dictionary / Index A adder's-tongue: Meaning and Definition of Find definitions for: ad•der's-tongue Pronunciation: (ad'urz-tung"), [key] — n. a fern of the genus Ophioglossum, having one or sometimes two sterile leaves and a fruiting spike. any of several American dogtooth violets. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: adder's-tongue (Thesaurus) adder's-mouth addict Related Content Daily Word Quiz: ounterfeit Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language