The poker term “dead money” is generally used to refer to money that is already in the pot from a bad or weak player or the blinds. It can be used more broadly to refer to any bet or raise that a player makes that he would not make normally to steal the dead money pre-flop. This includes forced bets such as stealing blinds and bluffing.
EXAMPLE “A new player who just joined the table posts a straddle, and it’s highly likely both blinds will fold. Seeing all that dead money in the pot, I am going to raise.”
In this video, Daniel Negreanu talks about “dead money” grabs.