saɪk.ləʊˈpiːd.i.ə ənˌsəɪ.kləˈpi.di.ə ɪnˌsaɪ.kləˈpi(ː).di.ə ənˌsəɪ.kləˈpi.di.ə ɪnˌsaɪ.kləˈpi(ː).di.ə a reference work (often in several volumes) containing articles on various topics (often arranged in alphabetical order) dealing with the entire range of human knowledge or with some particular specialty