laugh at vs rib

laugh at is not a noun while rib is a noun.

Word	Noun	Adjective	Verb	Adverb
laugh at	No	No	Yes	No
rib	Yes	No	Yes	No

As verbs, laugh at and rib are synonyms defined as:

Other synonyms of laugh at include blackguard, guy, jest at, make fun, poke fun, ridicule, roast.

laugh at (noun)	rib (noun)
	support resembling the rib of an animal
	a projecting molding on the underside of a vault or ceiling; may be ornamental or structural
	any of the 12 pairs of curved arches of bone extending from the spine to or toward the sternum in humans (and similar bones in most vertebrates)
	a riblike supporting or strengthening part of an animal or plant
	a teasing remark
	cut of meat including one or more ribs

laugh at (verb)	rib (verb)
subject to laughter or ridicule	subject to laughter or ridicule
	form vertical ribs by knitting