pecs vs pectoralis

pecs and pectoralis both are nouns.

Word	Noun	Adjective	Verb	Adverb
pecs	Yes	No	No	No
pectoralis	Yes	No	No	No

As nouns, pecs and pectoralis are synonyms defined as:

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

pecs (noun)	pectoralis (noun)
either of two large muscles of the chest	either of two large muscles of the chest