1. Not capable of being changed or altered
   - unalterable

See also: final, incurable, last

• tricentenary
• tricentennial
• triceps
• triceps brachii
• triceratops
• Trichechidae
• Trichechus
• Trichechus manatus
• trichiasis
• trichina
• Trichinella spiralis
• trichiniasis
• trichinosis
• trichion
• Trichiuridae
• trichloracetic acid
• trichloride
• trichlormethiazide
• trichloroacetic acid
• trichloroethane
• trichloroethylene
• trichloromethane
• trichobezoar
• Trichoceros
• trichodesmium