tormenter vs pest

tormenter and pest both are nouns.

Word	Noun	Adjective	Verb	Adverb
tormenter	Yes	No	No	No
pest	Yes	No	No	No

As nouns, pest is a hyponym of tormenter; that is, pest is a word with a more specific, narrower meaning than tormenter:

Other hyponyms of tormenter include harasser, blighter, cuss, gadfly, pesterer, tantaliser, tantalizer, witch-hunter.

tormenter (noun)	pest (noun)
a flat at each side of the stage to prevent the audience from seeing into the wings	any unwanted and destructive insect or other animal that attacks food or crops or livestock etc.
someone who torments	a persistently annoying person
	any epidemic disease with a high death rate
	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