trader vs dealer

trader and dealer both are nouns.

Word	Noun	Adjective	Verb	Adverb
trader	Yes	No	No	No
dealer	Yes	No	No	No

As nouns, trader and dealer are synonyms defined as:

trader and dealer: someone who purchases and maintains an inventory of goods to be sold

Other synonyms of trader include bargainer, monger.

trader (noun)	dealer (noun)
someone who purchases and maintains an inventory of goods to be sold	a firm engaged in trading
	a seller of illicit goods
	the person who distributes the playing cards in a card game
	someone who purchases and maintains an inventory of goods to be sold
	the major party to a financial transaction at a stock exchange; buys and sells for his own account