Definition of Triceps

Triceps: The triceps muscle extends (straightens) the elbow. Its full name is the triceps brachii. It can be felt as the tense muscle in the back of the upper arm while doing push-ups.

Its full name is the triceps brachii. The triceps has three heads, or origins. "Triceps" is Latin for three-headed and is derived from "tri", three + "caput", head.