rankle vs bother

rankle is not a noun while bother is a noun.

Word	Noun	Adjective	Verb	Adverb
rankle	No	No	Yes	No
bother	Yes	No	Yes	No

As verbs, bother is a hypernym of rankle; that is, bother is a word with a broader meaning than rankle:

Other hypernyms of rankle include annoy, chafe, devil, get at, get to, gravel, irritate, nark, nettle, rag, rile, vex.

rankle (noun)	bother (noun)
	something or someone that causes trouble; a source of unhappiness
	an angry disturbance

rankle (verb)	bother (verb)
gnaw into; make resentful or angry	cause annoyance in; disturb, especially by minor irritations
	make confused or perplexed or puzzled
	make nervous or agitated
	intrude or enter uninvited
	take the trouble to do something; concern oneself
	to cause inconvenience or discomfort to