Source : WordNet®

probabilistic
     adj 1: of or relating to the Roman Catholic philosophy of
            probabilism
     2: of or relating to or based on probability; "probabilistic
        quantum theory"

Source : Free On-Line Dictionary of Computing

probabilistic
     
         Relating to, or governed by, probability. The
        behaviour of a probabilistic system cannot be predicted
        exactly but the probability of certain behaviours is known.
        Such systems may be simulated using {pseudo-random} numbers.
        {Evolutionary computation} uses probabilistic processes to
        generate new (potential) solutions to a problem.
     
        See also {deterministic}, {non-probabilistic}.
     
        (1995-09-22)