Smithfield or Smoothfield, an open space of ground in London, N. of Newgate, long famous for its live-stock markets; in olden times lay outside the city walls, and was used as a place of recreation and of executions; the scene of William Wallace's execution and the death of Wat Tyler; gradually surrounded by the encroaching city, the cattle-market became a nuisance, and was abolished in 1855; is partly laid out as a garden.