cavity vs tar pit

cavity and tar pit both are nouns.

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

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

cavity: a sizeable hole (usually in the ground)
tar pit: a natural accumulation of bitumens at the surface of the earth; often acts as a trap for animals whose bones are thus preserved

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

cavity (noun)	tar pit (noun)
(anatomy) a natural hollow or sinus within the body	a natural accumulation of bitumens at the surface of the earth; often acts as a trap for animals whose bones are thus preserved
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