Pass is a short way of saying a player is opting out of the action. At the poker table it usually means giving up the hand: the player folds, forfeits whatever they have already put in the pot and sits out until the next deal. In some home games and older draw-poker rules, pass is also said when a player declines to bet while no bet is due, which modern card rooms call a check. Because the two uses differ, it pays to use the precise word at a live table.
In craps, the term has a separate meaning: a pass is a winning decision for the shooter, and the Pass Line bet takes its name from it. For online operators, clear action buttons such as Fold, Check and Call remove this ambiguity in poker interfaces and live dealer games.