E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Followers of Robert Brown, of Rutlandshire, a violent opponent of the Established Church in the time of Queen Elizabeth. The present Independents hold pretty well the same religious tenets as the Brownists. Sir Andrew Aguecheek says:
Id as lief be a Brownist as a politician.Shakespeare: Twelfth Night, iii. 2.