cavity vs borrow pit

cavity and borrow pit both are nouns.

Word	Noun	Adjective	Verb	Adverb
cavity	Yes	No	No	No
borrow pit	Yes	No	No	No

As nouns, borrow pit is a hyponym of cavity; that is, borrow pit is a word with a more specific, narrower meaning than cavity:

cavity: a sizeable hole (usually in the ground)
borrow pit: a pit created to provide earth that can be used as fill at another site

Other hyponyms of cavity include trou-de-loup, barbecue pit, divot, fire pit, quicksand, sandpit, sawpit, tar pit.

cavity (noun)	borrow pit (noun)
(anatomy) a natural hollow or sinus within the body	a pit created to provide earth that can be used as fill at another site
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