/ Dictionary / Index T trismus: Meaning and Definition of Find definitions for: tris•mus Pronunciation: (triz'mus, tris'-), [key] — pl. -mus•es. a spasm of the jaw muscles that makes it difficult to open the mouth. lockjaw. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: trismus (Thesaurus) Trismegistus trisoctahedron 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