/ Dictionary / Index T tuff: Meaning and Definition of Find definitions for: tuff Pronunciation: (tuf), [key] tough (def. 13). tuff Pronunciation: (tuf), [key] a fragmental rock consisting of the smaller kinds of volcanic detritus, as ash or cinder, usually more or less stratified. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: tuff (Thesaurus) tufa tuffet Related Content Daily Word Quiz: grimace Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language