To support one's opinions, judgements, etc., as to an undecided issue, by a wager or bet. to back a horse: to bet or stake money upon its winning a…

to put one's money on: to bet on; (figurative) to favour or depend on; to be confident of the success or reliability of.

Originally Betting. to put one's shirt on: to bet all one's money on a winner, outcome, etc.; to be sure of. Similarly also to bet (also stake) one…

transitive. colloquial (originally U.S.). To bet or gamble at or on (races, cards, etc.); to take chances with. to play a hunch (also one's hunches)…

To lay the whole of (a particular sum of money) on a single object.

To bet on (a horse).

Horse Racing. transitive. To bet money on (a horse) in a race, to back. Obsolete.

intransitive. Horse Racing. To stake money upon (a horse). Cf. to get on 9 at phrasal verbs 1. Obsolete.

Originally Betting. to put one's shirt on: to bet all one's money on a winner, outcome, etc.; to be sure of. Similarly also to bet (also stake) one…

(See quot. 1922.) So in to go a (or the) bundle on: to bet much money on; figurative to be very fond of. slang (originally U.S.).