mercer vs bargainer

mercer and bargainer both are nouns.

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

As nouns, bargainer is a hypernym of mercer; that is, bargainer is a word with a broader meaning than mercer:

mercer: a dealer in textiles (especially silks)
bargainer: someone who purchases and maintains an inventory of goods to be sold

Other hypernyms of mercer include dealer, monger, trader.

mercer (noun)	bargainer (noun)
a dealer in textiles (especially silks)	someone who purchases and maintains an inventory of goods to be sold
	negotiator of the terms of a transaction