n. One of an order of priests or ministers of religion among the ancient Celts of Gaul, Britain, and Ireland.n. A member of a society called the United Ancient Order of Druids, founded in London in 1781, for the mutual benefit of the members, and now counting numerous lodges, called groves, in America, Australia, Germany, etc.n. In entomology, a kind of saw-fly, a hyme-nopterous insect of the family Tenthredinidœ.