smock frock

plural smock frocks

1. A coarse frock, or shirt, worn over other clothing, as by farm labourers.

   He was often introduced into meetings through back doors, with a smock frock on his back, and a whip in his hand.

   1849, Thomas Babington Macaulay, The History of England from the Accession of James II, volume II, London: Longman, Brown, Green, and Longmans, →OCLC

   2 more examples

   What reason has he, therefore, to suppose that the return of the smock-frock will even increase the gobbling of potatoes and the drinking of cat-lap?

   1823, William Cobbett, Cobbett's Weekly Register, volume 46, page 777

   Among them we saw Rhys, and Llewellyn catching him by the smock-frock, as he came by him, pulled him out of the circle.

   1850, Thomas Keightley, The Fairy Mythology, London: H.G. Bohn, page 416