dealer

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun One that is engaged in buying and selling.
• noun Games The one who distributes cards.

from The Century Dictionary.

• noun In banking games, such as faro, the person who holds the cards which the players bet upon.
• noun One who deals; one who has to do or has concern with others; specifically, a trader; one whose business is to buy and sell, as a merchant, shopkeeper, or broker: as, a dealer in general merchandise or in stocks; a picture-dealer.
• noun In card-playing, the player who distributes the cards.

from the GNU version of the Collaborative International Dictionary of English.

• noun One who deals; one who has to do, or has concern, with others; esp., a trader, a trafficker, a shopkeeper, a broker, or a merchant
• noun One who distributes cards to the players.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun One who deals things, especially automobiles; a middleman.
• noun One who peddles illicit drugs, especially to teenagers.
• noun A particular type of stock broker or trader.
• noun The person who deals the cards in a card game.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

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