chest vs pectus

chest and pectus both are nouns.

Word	Noun	Adjective	Verb	Adverb
chest	Yes	No	No	No
pectus	Yes	No	No	No

As nouns, chest and pectus are synonyms defined as:

chest and pectus: the part of the human torso between the neck and the diaphragm or the corresponding part in other vertebrates

Other synonyms of chest include thorax.

chest (noun)	pectus (noun)
box with a lid; used for storage; usually large and sturdy	the part of the human torso between the neck and the diaphragm or the corresponding part in other vertebrates
furniture with drawers for keeping clothes
the part of the human torso between the neck and the diaphragm or the corresponding part in other vertebrates
the front of the trunk from the neck to the abdomen