Cow Up (poker)
Go half and half with a player on his buy-in to a game; usually
preceded by go; sometimes followed by up. When the player quits,
he splits with the person with whom he went cow. Sometimes the
house goes cow with a player to enable him to get into a larger
game than he could otherwise afford, generally with the no altruistic
purpose of filling what would otherwise be a shaky game. At
some point when the player (the house hopes) gets far
enough ahead of the game, the house may split him out, that
is, remove half of his chips and put him on his own.