Noun

1. a clandestine payment in return for a favor; especially an illegal one
2. recoil; a sudden backward motion, usually in the direction of the operator.
3. an accident wherein an object being cut by a rotating blade or disk, such as a circular saw, is caught by the blade and thrown outward
4. a dangerous buildup of gas pressure at the wellhead
5. the board separating one bowling lane from another at the pit end
6. In contract bridge, an ace asking convention initiated by the first step above four of the agreed trump suit.