(n.) The system of religion, philosophy, and instruction, received and taught by the Druids; the rites and ceremonies of the Druids.
Example Sentences:
(1) As inventions of bogus deep-time traditions go, British druidism has to be one of the most enduringly successful.
(2) Druidism can be seen as another quasi-Masonic phenomenon, and druids of this ilk are on a par with any other odd fellows, their aim being clubbable mutual assistance rather than mystical transcendence.