/prob'euh bil"i tee/ , n. , pl. probabilities .
1. the quality or fact of being probable.
2. a strong likelihood or chance of something: The probability of the book's success makes us optimistic.
3. a probable event, circumstance, etc.: Our going to China is a probability.
4. Statistics.
a. the relative possibility that an event will occur, as expressed by the ratio of the number of actual occurrences to the total number of possible occurrences.
b. the relative frequency with which an event occurs or is likely to occur.
5. in all probability , very probably; quite likely: The factory will in all probability be relocated.
[ 1545-55; probabilitas. See PROBABLE, -ITY ]