(1) CLERK. As in ancient times the clergyman was about the only person who could write and read, the word clerical, as used in “clerical error,” came to signify an orthographical error. As the respondent in church was able to read, he received the name of clerk, and the assistants in writing, etc., are so termed in business.
(Latin, clericus, a clergyman.)
(2) CURATE. One who has the cure of souls. As the cure of the parish used to be virtually entrusted to the clerical stipendiary, the word curate was appropriated to this assistant.
(3) RECTOR. One who has the parsonage and great tithes. The man who rules or guides the parish. (Latin, “a ruler.”)
(4) VICAR. One who does the “duty” of a parish for the person who receives the tithes. (Latin, vicarius, a deputy.)
(5) INCUMBENT and PERPETUAL CURATE are now termed Vicars. (See Parsons)
The French curé equals our vicar, and their vicaire our curate.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894