"1952: The surface of the parget might be finished either smooth, with a coat of
whitewash, or as rough-cast with sand or small stones. — L.F. Salzman, Building in England, p. 191."
(v) :
to coat with parget; to plaster, as
walls, or the interior of flues; as, to parget the outside of their houses; to paint; to cover over. [Obs.]