musculus deltoideus vs rotator cuff

musculus deltoideus and rotator cuff both are nouns.

Word	Noun	Adjective	Verb	Adverb
musculus deltoideus	Yes	No	No	No
rotator cuff	Yes	No	No	No

musculus deltoideus (noun)	rotator cuff (noun)
a large triangular muscle covering the shoulder joint and serving to abduct and flex and extend and rotate the arm	a supporting structure of the shoulder consisting of the muscles and tendons that attach the arm to the shoulder joint and enable the arm to move