pyx vs chest

pyx and chest both are nouns.

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

As nouns, chest is a hypernym of pyx; that is, chest is a word with a broader meaning than pyx:

pyx (noun)	chest (noun)
any receptacle in which wafers for the Eucharist are kept	box with a lid; used for storage; usually large and sturdy
a chest in which coins from the mint are held to await assay	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