bargainer vs bibliopole

bargainer and bibliopole both are nouns.

Word	Noun	Adjective	Verb	Adverb
bargainer	Yes	No	No	No
bibliopole	Yes	No	No	No

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

bargainer: someone who purchases and maintains an inventory of goods to be sold
bibliopole: a dealer in secondhand books (especially rare or curious books)

bargainer (noun)	bibliopole (noun)
someone who purchases and maintains an inventory of goods to be sold	a dealer in secondhand books (especially rare or curious books)
negotiator of the terms of a transaction