plague vs get at

plague is a noun but get at is not a noun.

Word	Noun	Adjective	Verb	Adverb
plague	Yes	No	Yes	No
get at	No	No	Yes	No

As verbs, get at is a hypernym of plague; that is, get at is a word with a broader meaning than plague:

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

plague (noun)	get at (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

plague (verb)	get at (verb)
annoy continually or chronically	cause annoyance in; disturb, especially by minor irritations
cause to suffer a blight	reach or gain access to
	influence by corruption