Definition of Scots plough in US English:

Scots plough

(US Scots plow)

noun

historical
  • A type of swing plough, made chiefly (sometimes wholly) from wood, and drawn by a team of up to eight horses or oxen (also more fully "old Scots plough"); (also) a lighter type of swing plough which can be drawn by two horses, especially one made entirely from cast iron.

Origin

Mid 18th century; earliest use found in Adam Dickson (bap. 1721, d. 1776), agricultural writer.