Definition of trismus in US English:



  • Spasm of the jaw muscles, causing the mouth to remain tightly closed, typically as a symptom of tetanus.

    Also called lockjaw
    • ‘Muscle tone is increased, producing the characteristic trismus, ‘risus sardonicus,’ and opisthotonus.’
    • ‘The presenting symptoms include fever, throat pain, and trismus.’
    • ‘Regional lymphadenopathy is common, and cellulitis and trismus (inability to open the mouth fully) can occur.’
    • ‘He developed jaw muscle spasm or trismus (from the word ‘grinding’ in Greek), difficulty swallowing, and stiffness or pain in the neck, shoulder and back muscles.’
    • ‘The most common dystonias involve the muscles of the head and face producing buccal spasms, oculogyric crisis, facial grimacing, tics, or trismus.’


Late 17th century: from modern Latin, from Greek trismos ‘a scream, grinding’.