ETYM Old Eng. plouh, plou, as. plôh; akin to Dutch ploeg, German pflug, Old High Germ. pfluog, pfluoh, Icel. plôgr, Swed. plog, Dan. ploug, plov, Russ. plug, Lith. plugas.
The most important agricultural implement used for tilling the soil. The plow dates from about 3500 bc, when oxen were used to pull a simple wooden blade, or ard. In about 500 bc the iron share came into use.
By about ad 1000 horses as well as oxen were being used to pull wheeled plows, equipped with a plowshare for cutting a furrow, a blade for forming the walls of the furrow (called a colter), and a moldboard to turn a furrow. In the 18th century an innovation introduced by Robert Ransome (1753–1830) led to a reduction in the number of animals used to draw a plow: from an 8–12 oxer, or 6 horses, to a 2- or 4-horse plow. Steam plows came into use in some areas in the 1860s, superseded half a century later by tractor-drawn plows. The present plow consists of many “bottoms,” each comprising a curved plowshare and angled moldboard. The bottom is designed so that it slices into the ground and turns the soil over.
A farm tool having one or more heavy blades to break the soil and cut a furrow prior to sowing; SYN. plough.

1. To move in a way resembling that of a plow cutting into or going through the soil; SYN. plough.
2. To break and turn over earth esp. with a plow; SYN. plough, turn.