afflict vs plague

afflict is not a noun while plague is a noun.

Word	Noun	Adjective	Verb	Adverb
afflict	No	No	Yes	No
plague	Yes	No	Yes	No

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

Other hyponyms of afflict include visit, blight.

afflict (noun)	plague (noun)
	an annoyance
	any large scale calamity (especially when thought to be sent by God)
	a swarm of insects that attack plants
	a serious (sometimes fatal) infection of rodents caused by Yersinia pestis and accidentally transmitted to humans by the bite of a flea that has bitten an infected animal
	any epidemic disease with a high death rate

afflict (verb)	plague (verb)
cause physical pain or suffering in	annoy continually or chronically
cause great unhappiness for; distress	cause to suffer a blight