slough vs cast off

slough is a noun but cast off is not a noun.

Word	Noun	Adjective	Verb	Adverb
slough	Yes	No	Yes	No
cast off	No	No	Yes	No

As verbs, cast off is a hypernym of slough; that is, cast off is a word with a broader meaning than slough:

Other hypernyms of slough include cast, drop, shake off, shed, throw, throw away, throw off.

slough (noun)	cast off (noun)
any outer covering that can be shed or cast off (such as the cast-off skin of a snake)
necrotic tissue; a mortified or gangrenous part or mass
a stagnant swamp (especially as part of a bayou)
a hollow filled with mud

slough (verb)	cast off (verb)
cast off hair, skin, horn, or feathers	to remove
	make the last row of stitches when knitting