cavity vs trou-de-loup

cavity and trou-de-loup both are nouns.

Word	Noun	Adjective	Verb	Adverb
cavity	Yes	No	No	No
trou-de-loup	Yes	No	No	No

As nouns, trou-de-loup is a hyponym of cavity; that is, trou-de-loup is a word with a more specific, narrower meaning than cavity:

cavity: a sizeable hole (usually in the ground)
trou-de-loup: a sloping pit with a stake in the middle used as an obstacle to the enemy

Other hyponyms of cavity include barbecue pit, borrow pit, divot, fire pit, quicksand, sandpit, sawpit, tar pit.

cavity (noun)	trou-de-loup (noun)
(anatomy) a natural hollow or sinus within the body	a sloping pit with a stake in the middle used as an obstacle to the enemy
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