Source : Webster's Revised Unabridged Dictionary (1913)

Plymouth Brethren \Plym"outh Breth"ren\
   The members of a religious sect which first appeared at
   Plymouth, England, about 1830. They protest against
   sectarianism, and reject all official ministry or clergy.
   Also called {Brethren}, {Christian Brethren}, {Plymouthists},
   etc. The {Darbyites} are a division of the Brethren.