cofferdam vs chamber

cofferdam and chamber both are nouns.

Word	Noun	Adjective	Verb	Adverb
cofferdam	Yes	No	No	No
chamber	Yes	No	Yes	No

As nouns, chamber is a hypernym of cofferdam; that is, chamber is a word with a broader meaning than cofferdam:

cofferdam (noun)	chamber (noun)
large watertight chamber used for construction under water	a natural or artificial enclosed space
	a room used primarily for sleeping
	a room where a judge transacts business
	an enclosed volume in the body
	a deliberative or legislative or administrative or judicial assembly

cofferdam (verb)	chamber (verb)
	place in a chamber