/ Dictionary / Index T tach: Meaning and Definition of Find definitions for: tach Pronunciation: (tak), [key] — n. Informal. tachometer. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: tach (Thesaurus) tacet tache Related Content Daily Word Quiz: profiterole Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language