Okishian /əʊˈkɪ.ʃi.ən/ adjective1 •Of or pertaining to the Japanese economist Nobuo Okishio and his theories.The generality of the Okishian theorem has thus been refuted, and that theorem is thus confined to a special case (i.e. neoclassical-perfect competition in the absence of fixed capital). — 1991 formsmore Okishian · most Okishian