Walk
If you sit at the Big Blind and all other players decide to Fold you will win the Pot without doing anything - this is called a Walk (yes, it is a Baseball term - well done).
WCOOP
World Championship of Online Poker.
Weak Ace
If your Pocket Cards are made up of an Ace and a low Kicker you hold a Weak Ace. For example A4.
Wheel
The smallest possible Straight (A2345).
Wired Pair
A less common term for Pocket Pair.
WPT
World Poker Tour.
WSOP
Word Series of Poker.