chest vs caisson

chest and caisson both are nouns.

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

As nouns, caisson is a hyponym of chest; that is, caisson is a word with a more specific, narrower meaning than chest:

chest (noun)	caisson (noun)
box with a lid; used for storage; usually large and sturdy	large watertight chamber used for construction under water
furniture with drawers for keeping clothes	an ornamental sunken panel in a ceiling or dome
the part of the human torso between the neck and the diaphragm or the corresponding part in other vertebrates	a chest to hold ammunition
the front of the trunk from the neck to the abdomen	a two-wheeled military vehicle carrying artillery ammunition