sit down vs scrunch up

sit down and scrunch up both are verbs.

Word	Noun	Adjective	Verb	Adverb
sit down	No	No	Yes	No
scrunch up	No	No	Yes	No

As verbs, scrunch up is a hyponym of sit down; that is, scrunch up is a word with a more specific, narrower meaning than sit down:

sit down: be in a position in which one's upper body is largely upright and supported by one's backside
scrunch up: sit on one's heels

Other hyponyms of sit down include lounge, sprawl, perch, rest, roost, crouch, hunker, hunker down, scrunch, squat.

sit down (verb)	scrunch up (verb)
show to a seat; assign a seat for	make wrinkles or creases on a smooth surface; make a pressed, folded or wrinkled line in; `crisp' is archaic
be in a position in which one's upper body is largely upright and supported by one's backside	sit on one's heels
take a seat