nagger vs harridan

nagger and harridan both are nouns.

Word	Noun	Adjective	Verb	Adverb
nagger	Yes	No	No	No
harridan	Yes	No	No	No

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

nagger: someone (especially a woman) who annoys people by constantly finding fault
harridan: a scolding (even vicious) old woman

nagger (noun)	harridan (noun)
someone (especially a woman) who annoys people by constantly finding fault	a scolding (even vicious) old woman