Medical Definition of longus
: a long structure (as a muscle) in the body—see abductor pollicis longus, adductor longus, extensor carpi radialis longus, extensor digitorum longus, extensor hallucis longus, extensor pollicis longus, flexor digitorum longus, flexor hallucis longus, flexor pollicis longus, palmaris longus, peroneus longus
Seen and Heard
What made you want to look up longus? Please tell us where you read or heard it (including the quote, if possible).