Dog
A shortened version of the term underdog. An underdog is either a player who is not favored against the competition, or a hand that is a statistically weaker against the other hands involved in a pot.
Dominated Hand
A situation in which one player's hand is a heavy statistical underdog to another player's hand. A typical example would be when one player holds a pair of Aces to another other player's Kings. The Kings are heavily dominated as they must catch one of the other Kings to win the hand.
Door Card
The first card dealt face up in a Stud game after the hole cards are dealt.
Draw Dead
A situation in which a player is on a draw but will not win the pot even if they make their hand. An example would be a player calling bets in hopes of making a flush when their opponent has already made a full house.
Drop
Another term for folding cards. A player can be said to "drop" their hand.