musculus trapezius vs trapezius

musculus trapezius and trapezius both are nouns.

Word	Noun	Adjective	Verb	Adverb
musculus trapezius	Yes	No	No	No
trapezius	Yes	No	No	No

As nouns, musculus trapezius and trapezius are synonyms defined as:

musculus trapezius and trapezius: either of two flat triangular muscles of the shoulder and upper back that are involved in moving the shoulders and arms

Other synonyms of musculus trapezius include cowl muscle, trapezius muscle.

musculus trapezius (noun)	trapezius (noun)
either of two flat triangular muscles of the shoulder and upper back that are involved in moving the shoulders and arms	either of two flat triangular muscles of the shoulder and upper back that are involved in moving the shoulders and arms