crouch vs hunker down

crouch is a noun but hunker down is not a noun.

Word	Noun	Adjective	Verb	Adverb
crouch	Yes	No	Yes	No
hunker down	No	No	Yes	No

As verbs, crouch and hunker down are synonyms defined as:

Other synonyms of crouch include hunker, scrunch, scrunch up, squat.

crouch (noun)	hunker down (noun)
the act of bending low with the limbs close to the body

crouch (verb)	hunker down (verb)
sit on one's heels	hold stubbornly to a position
bend one's back forward from the waist on down	sit on one's heels
	take shelter