pecs vs pectoral muscle

pecs and pectoral muscle both are nouns.

Word	Noun	Adjective	Verb	Adverb
pecs	Yes	No	No	No
pectoral muscle	Yes	No	No	No

As nouns, pecs and pectoral muscle are synonyms defined as:

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

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