hunker vs hunker down

hunker and hunker down both are verbs.

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

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

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

hunker (verb)	hunker down (verb)
sit on one's heels	hold stubbornly to a position
	sit on one's heels
	take shelter