deltoid

[ del-toid ]
/ ˈdɛl tɔɪd /

noun

Anatomy. a large, triangular muscle covering the joint of the shoulder, the action of which raises the arm away from the side of the body.

adjective

Anatomy. pertaining to or involving the deltoid.
Also deltoidal. in the shape of a Greek capital delta (Δ); triangular.

Origin of deltoid

1675–85; < Greek deltoeidḗs delta-shaped, equivalent to délt(a) delta + -oeidēs -oid

OTHER WORDS FROM deltoid

sub·del·toid, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for deltoid

British Dictionary definitions for deltoid

deltoid
/ (ˈdɛltɔɪd) /

noun

the thick muscle forming the rounded contour of the outer edge of the shoulder and acting to raise the arm

adjective

shaped like a Greek capital delta, Δ; triangular

Word Origin for deltoid

C18: from Greek deltoeidēs triangular, from delta
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for deltoid

deltoid
[ dĕltoid′ ]

adj.

Of or relating to the deltoid muscle.
Triangular in shape or outline.

n.

The deltoid muscle.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.