https://en.wikipedia.org/wiki/Chapman_(surname)
Chapman is an English surname derived from the Old English occupational name céapmann "marketman, monger, merchant", from the verb céapan, cypan "to buy or sell" and the noun form ceap "barter, business, purchase." Alternate spellings include Caepmon, Cepeman, Chepmon, Cypman(n), and Shapman. (By 1600, the occupational name chapman had come to be applied …