a person who buys and sells articles without altering their condition; trader or merchant, esp. a wholesaler

I got a dealer's discount on this coat.

Cards . the player distributing the cards.

a person who behaves or acts toward another or others in a specified manner

a plain dealer.

Slang . a person who buys and sells drugs illegally.

a person who buys securities for his or her account and retains them until sold to another.

noun

customer

noun

banker , bursar , businessperson , chandler , changer , dispenser , marketer , merchandiser , merchant , retailer , trader , tradesperson , trafficker , vendor , wholesaler , speculator , tradesman , peddler , agent , broker , businessman , businesswoman , commission dealer , distributor , jobber , mercer , middleman , middleperson , monger , negotiator , operator , seller , shopkeeper , tradeswoman , vender