deltoid
nounUK /ˈdɛltɔɪd/
US /ˈdɛltɔɪd/
The deltoid is the big muscle on your shoulder that helps you lift your arm.
He hurt his deltoid while throwing the ball.
RELATED WORDS
OTHER MEANINGS
2. Shaped like a triangle or the Greek letter delta.
The leaf had a deltoid shape.
3. A four-sided figure with two pairs of equal sides, like a kite.
The geometry teacher drew a deltoid on the board.
4. The triangular flap of a garment covering the shoulder.
The jacket's deltoid was reinforced with extra stitching.