Английский Этимологический словарь - mock (v)

- early 15c., from M.Fr. mocquer "deride, jeer," from O.Fr., perhaps from V.L. *muccare "to blow the nose" (as a derisive gesture), from L. mucus; or possibly from M.Du. mocken "to mumble" or M.L.G. mucken "grumble." Replaced O.E. bysmerian. Sense of "imitating" (mocking-bird, mock turtle, etc.) is from notion of derisive imitation. The adj. is 1548, from the noun. Mock-up "model, simulation" is from 1920.