Entry 1 sense Webster, 1913 Cytococcus /(-k?k"k?s)/ · Cy·to·coc·cus · IPA /ˌsaɪtəˈkɑkəs/ 01 n. The nucleus of the cytula or parent cell. pl. Cytococci ((-s�)) 1. The nucleus of the cytula or parent cell.(Biol.)