piston chamber vs pump

piston chamber and pump both are nouns.

Word	Noun	Adjective	Verb	Adverb
piston chamber	Yes	No	No	No
pump	Yes	No	Yes	No

piston chamber (noun)	pump (noun)
a chamber within which piston moves	a mechanical device that moves fluid or gas by pressure or suction
	a low-cut shoe without fastenings
	the hollow muscular organ located behind the sternum and between the lungs; its rhythmic contractions move the blood through the body

piston chamber (verb)	pump (verb)
	question persistently
	deliver forth
	operate like a pump; move up and down, like a handle or a pedal
	raise (gases or fluids) with a pump
	draw or pour with a pump
	flow intermittently
	move up and down
	supply in great quantities