It’s interesting to think about how words were invented.

You may think that EDITOR was formed from EDIT. No, you are wrong. EDITOR was in use long before EDIT. EDITOR came into use in 1649; EDIT appeared in 1791 with the deletion of OR. — O.A. Booty, “Funny Side of English” p. 29

Edit arose because the word editor sounds as if it should mean “one who edits.”

Middle English “pease” was a mass noun already in wide use, but people assumed it was plural. So they came up with “pea.”