tʃæns pɹɒbəˈbɪlɪti pɹɑbəˈbɪlɪɾi the quality of being probable; a probable event or the most probable event for a while mutiny seemed a probability going by past experience, there was a high probability that the visitors were lost 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 if that phone call is for me, chances are it's my wife