pectoral muscle vs musculus pectoralis

pectoral muscle and musculus pectoralis both are nouns.

Word	Noun	Adjective	Verb	Adverb
pectoral muscle	Yes	No	No	No
musculus pectoralis	Yes	No	No	No

As nouns, pectoral muscle and musculus pectoralis are synonyms defined as:

pectoral muscle and musculus pectoralis: either of two large muscles of the chest

Other synonyms of pectoral muscle include pecs, pectoral, pectoralis.

pectoral muscle (noun)	musculus pectoralis (noun)
either of two large muscles of the chest	either of two large muscles of the chest