Chance
WordNet
noun
(1) A risk involving danger
"You take a chance when you let her drive"
(2) A 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"
(3) An unknown and unpredictable phenomenon that causes an event to result one way rather than another
"Bad luck caused his downfall"
"We ran into each other by pure chance"
(4) The possibility of future success
"His prospects as a writer are excellent"
(5) A possibility due to a favorable combination of circumstances
"The holiday gave us the opportunity to visit Washington"
"Now is your chance"
verb
(6) Take a risk in the hope of a favorable outcome
"When you buy these stocks you are gambling"
(7) Be the case by chance
"I chanced to meet my old friend in the street"