druid

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A member of an order of priests in ancient Gaul and Britain who appear in Welsh and Irish legend as prophets and sorcerers.

Century Dictionary and Cyclopedia

1. n. One of an order of priests or ministers of religion among the ancient Celts of Gaul, Britain, and Ireland. The chief seats of the druids were in Wales, Brittany, and the regions around the modern Dreux and Chartres in France. The druids are believed to have possessed some knowledge of geometry, natural philosophy, etc. They superintended the affairs of religion and morality, and performed the office of judges. The oak is said to have represented to them the one supreme God, and the mistletoe when growing upon it the dependence of man upon him; and they accordingly held these in the highest veneration, oak-groves being their places of worship. They are said to have had a common superior, who was elected by a majority of votes from their own members, and who enjoyed his dignity for life. The druids, as an order, always opposed the Romans, but were ultimately exterminated by them.
2. 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.
3. n. In entomology, a kind of saw-fly, a hyme-nopterous insect of the family Tenthredinidœ.

Wiktionary

1. n. One of an order of priests among certain groups of Celts before the adoption of Christianity.

GNU Webster's 1913

1. n. One of an order of priests which in ancient times existed among certain branches of the Celtic race, especially among the Gauls and Britons.
2. n. A member of a social and benevolent order, founded in London in 1781, and professedly based on the traditions of the ancient Druids. Lodges or groves of the society are established in other countries.

WordNet 3.0

1. n. a pre-Christian priest among the Celts of ancient Gaul and Britain and Ireland