sawpit vs cavity

sawpit and cavity both are nouns.

Word	Noun	Adjective	Verb	Adverb
sawpit	Yes	No	No	No
cavity	Yes	No	No	No

As nouns, cavity is a hypernym of sawpit; that is, cavity is a word with a broader meaning than sawpit:

sawpit: a pit over which lumber is positioned to be sawed by two men with a long two-handed saw
cavity: a sizeable hole (usually in the ground)

Other hypernyms of sawpit include pit.

sawpit (noun)	cavity (noun)
a pit over which lumber is positioned to be sawed by two men with a long two-handed saw	(anatomy) a natural hollow or sinus within the body
	a sizeable hole (usually in the ground)
	soft decayed area in a tooth; progressive decay can lead to the death of a tooth
	space that is surrounded by something