incogitable

英 [ɪn'kɒdʒɪtəbl] 美[ɪn'kɑdʒətəbl]

incogitable (adj.): "unthinkable," 1520s, from Late Latin incogitabilis, from in- "not" (see in- (1)) + cogitabilis, from stem of cogitare (see cogitation).