/ Dictionary / Index T thumbprint: Meaning and Definition of Find definitions for: thumb•print Pronunciation: (thum'print"), [key] — n. a mark or impression of the ventral surface of the last joint of the thumb. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: thumbprint (Thesaurus) thumbpiece thumbscrew Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language