ichthyologyEnglishOxford Dictionary of Englishichthyology /ˌɪkθiˈɒlədʒi / ▸ noun [mass noun] the branch of zoology that deals with fishes. – DERIVATIVES ichthyological /ˌɪkθiəˈlɒdʒɪkl / adjective ichthyologist /ˌɪkθiˈɒlədʒɪst / noun