Definition of bet:
(n) :
a
wager, an agreement between two parties that a stake (usually money) will be paid by the loser to the winner the one who correctly forcast the outcome of an event; a degree of
certainty
"it's a good bet that it will rain tomorrow."
(v) :
to agree that payment be made to the successful forecaster of the result of an event (usually sporting) by the other party in the agreement. To make a
guess about the
outcome of an event; to be
sure of something; to be able to
count on something
"you bet!"