pest vs nudnik

pest and nudnik both are nouns.

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

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

Other hyponyms of pest include nudnick.

pest (noun)	nudnik (noun)
any unwanted and destructive insect or other animal that attacks food or crops or livestock etc.	(Yiddish) someone who is a boring pest
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