Green’s Dictionary of Slang

a parson who rushes through the service.

1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1878		Isle of Wight Obs. 28 Dec. 6/5: ‘It is well to be a postillion to the Gospel at these rates,’ says the sarcastic Clement Walker.