Also called the vig, juice, cut, or take. Essentially, it's the bookmaker's commission, collected no matter what the outcome. In investment banking, the charge for giving advice is sometimes called the vig. The word started as American slang from around 1910, formerly also spelled viggresh, from Yiddish, from either Ukrainian výgrash or Russian výigrysh, winnings/profit, from vy-, out + igrat', to play -- so originally something like the pay-off.
Expect regulators to slap still more restraints on Comcast as a vigorish for letting it buy Time Warner Cable.