What is "to hedge a bet"

Hedge \Hedge\, v. t. [imp. & p. p. Hedged; p. pr. & vb. n. Hedging.]

1. To inclose or separate with a hedge; to fence with a thickly set line or thicket of shrubs or small trees; as, to hedge a field or garden.

2. To obstruct, as a road, with a barrier; to hinder from progress or success; -- sometimes with up and out.

   I will hedge up thy way with thorns.
   --Hos. ii. 6.

   Lollius Urbius . . . drew another wall . . . to hedge out incursions from the north.
   --Milton.

3. To surround for defense; to guard; to protect; to hem (in). ``England, hedged in with the main.''
   --Shak.

4. To surround so as to prevent escape.

   That is a law to hedge in the cuckoo.
   --Locke.

5. To protect oneself against excessive loss in an activity by taking a countervailing action; as, to hedge an investment denominated in a foreign currency by buying or selling futures in that currency; to hedge a donation to one political party by also donating to the opposed political party.

   To hedge a bet, to bet upon both sides; that is, after having bet on one side, to bet also on the other, thus guarding against loss. See hedge[5].