Gilamonster

WordReference Random House Learner's Dictionary of American English © 2026

Gi•la mon•ster /ˈhilə ˌmɑnstɚ/  n. [countable]

1. Reptiles a large, poisonous lizard of the SW United States and NW Mexico, covered with beadlike scales of yellow, orange, and black.

WordReference Random House Unabridged Dictionary of American English © 2026

Gi′la mon′ster, 

1. Reptiles a large, venomous lizard, Heloderma suspectum, of the southwestern U.S. and northwestern Mexico, covered with beadlike scales of yellow, orange, and black.

• after Gila 1875–80, American.

Collins Concise English Dictionary © HarperCollins Publishers::

Gila monster / ˈhiːlə/ noun

1. a large venomous brightly coloured lizard, Heloderma suspectum, inhabiting deserts of the southwestern US and Mexico and feeding mostly on eggs and small mammals: family Helodermatidae
   Also called: Gila

Etymology: 19th Century: after the Gila, a river in New Mexico and Arizona