sto·chas·tic I. \stəˈkastik\adjective Etymology: Greek stochastikos skillful in aiming, proceeding by guesswork, from (assumed) stochastos (verbal of stochazesthai to aim at, guess at, from stochos target, aim, guess) + -ikos -ic — more at sting : random < stochastic processes > < stochastic variables > II. adjective : involving chance or probability : probabilistic < a stochastic model of radiation-induced mutation > • stochasticallyadverb