1610s, earlier bucolical (1520s), from Latin bucolicus, from Greek boukolikos "pastoral, rustic," from boukolos "cowherd, herdsman," from bous "cow" (see cow, n.) + -kolos "tending," related to Latin colere "to till (the ground), cultivate, dwell, inhabit" (the root of colony). Middle Irish búachaill, Welsh bugail "shepherd" are Celtic words form from the same root material as Greek boukolos.