Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English


English definition of “deltoid”


noun [C] /ˈdel.tɔɪd/ (also deltoid muscle) specialized
a muscle in the shoulder , shaped like a triangle and used for lifting the arm : Always stretch your deltoids after lifting weights . The deltoid muscle lifts the arm sideways .
(Definition of deltoid noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)

Word of the Day


a skilled and trained cook who works in a hotel or restaurant, especially the most important cook

Word of the Day


Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More