un·pre·dict·a·ble 
(ŭn′prĭ-dĭktə-bəl)
(ŭn′prĭ-dĭktə-bəl)adj.
Difficult to foretell or foresee: unpredictable test results; unpredictable behavior.
n.
Something difficult or impossible to foretell or foresee.
un′pre·dict′a·bili·ty n.
un′pre·dicta·bly adv.