/'swi:psteɪk; `swip,stek/
(also infml 口语作 sweep) n
(a) type of gambling in which all the money bet on the result of a contest is divided among those who by chance have selected or been given tickets corresponding to the eventual winner(s) of the contest 赌金全赢制（胜者可获全部赌金者）.
(b) horse-race on which money is bet in this way 实行赌金全赢制的赛马.

nsweepstakesAmE[C]
[Date: 1700-1800; Origin: sweepstake 'someone who takes all the winnings in a game' (15-18 centuries), from sweep + stake]
a type of betting in which the winner receives all the money risked by everyone else
AmE a type of competition in which you have the chance to win a prize if your name is chosen
AmE a competition, election etc in which no one knows who will be the winner
　the presidential sweepstakes