Source : WordNet®

unknowable
     adj 1: not knowable [ant: {knowable}]
     2: beyond and outside the ordinary range of human experience or
        understanding; "philosophers...often explicitly reject the
        notion of any transcendent reality beyond thought...and
        claim to be concerned only with thought itself..."-
        W.P.Alston; "the unknowable mysteries of lifer" [syn: {transcendent}]