rubaiyat

‖n. pl.; sing. Rubai /sing>. [ Ar. rubā'iyāh quatrian, pl. of rubā'iy having four radicals, fr. rubā' four. ] Quatrians; as, the Rubaiyat of Omar Khayyam. Sometimes in pl. construed as sing., a poem in such stanzas. [ Webster 1913 Suppl. ]