scrunch up vs ruck up

scrunch up and ruck up both are verbs.

Word	Noun	Adjective	Verb	Adverb
scrunch up	No	No	Yes	No
ruck up	No	No	Yes	No

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

scrunch up: make wrinkles or creases on a smooth surface; make a pressed, folded or wrinkled line in; `crisp' is archaic
ruck up: become wrinkled or drawn together

Other hyponyms of scrunch up include cockle, crumple, knit, pucker, rumple, pucker, ruck.

scrunch up (verb)	ruck up (verb)
make wrinkles or creases on a smooth surface; make a pressed, folded or wrinkled line in; `crisp' is archaic	become wrinkled or drawn together
sit on one's heels