ruckle vs cockle

ruckle is not a noun while cockle is a noun.

Word	Noun	Adjective	Verb	Adverb
ruckle	No	No	Yes	No
cockle	Yes	No	Yes	No

As verbs, cockle is a hyponym of ruckle; that is, cockle is a word with a more specific, narrower meaning than ruckle:

ruckle: make wrinkles or creases on a smooth surface; make a pressed, folded or wrinkled line in; `crisp' is archaic
cockle: to gather something into small wrinkles or folds

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

ruckle (noun)	cockle (noun)
	common edible, burrowing European bivalve mollusk that has a strong, rounded shell with radiating ribs
	common edible European bivalve

ruckle (verb)	cockle (verb)
make wrinkles or creases on a smooth surface; make a pressed, folded or wrinkled line in; `crisp' is archaic	to gather something into small wrinkles or folds
make a hoarse, rattling sound	stir up (water) so as to form ripples