Open English Wordnet
Nouns
(n)opportunity, chancea possibility due to a favorable combination of circumstances“the holiday gave us the opportunity to visit Washington”, “now is your chance”
(n)probability, chancea measure of how likely it is that some event will occur; a number expressing the ratio of favorable cases to the whole number of cases possible“the probability that an unbiased coin will fall with the head up is 0.5”, “if that phone call is for me, chances are it's my wife”
Verbs
(v)gamble, chance, risk, hazard, take chances, adventure, run a risk, take a chancetake a risk in the hope of a favorable outcome“When you buy these stocks you are gambling”