A poker term to describe a hand in which all the players at the table enter the pot. This happens rarely in games with high limits or among "good" players, but in some home games every player always plays every hand at least through the first round. In low-limit poker played in your local casino or cardroom you'll sometimes find a very loose game where family pots are common.
In a poker game where everyone enters the pot it greatly increases the variance in your bankroll. Even if you are the best player at the table it can often take many hours before you get a winning hand at showdown. Bluffing in a family pot is almost guaranteed not to work. The pot is too large for at least one of the players not to call you.