plough often used emblematically, as in follow the plough meaning be a ploughman or farmer.

From late Middle English, the Plough has been the name given to a prominent formation of seven stars in the constellation Ursa Major (the Great Bear), containing the Pointers that indicate the direction to the Pole Star. Also called (in North America) the Big Dipper and (formerly, in Britain) Charles's Wain.
plough a lonely furrow carry on without help or companionship. The earliest recorded form of this phrase is found in a speech by Lord Rosebery of July 1901.
Plough Monday the first Monday after Epiphany, formerly marked by popular festivals or observances in some regions, especially the north and east of England, named from the custom of dragging a plough through the streets to mark the beginning of the ploughing season.
ploughshare the main cutting blade of a plough, often with biblical allusion to Isaiah 2:4 (see beat swords into ploughshares).
plough the sands undertake an impossible or pointless task; first recorded in Robert Greene's Never Too Late (1590).

See also put one's hand to the plough.

plough / plou/ • n. & v. British spelling of plow. ∎  (the Plough) British term for Big Dipper.

plough, U.S. plow implement for cutting furrows in soil. Late OE. plōh — ON. plógr = OS. plōg (Du. ploeg), OHG. phluog (G. pflug):- Gmc. *plōʒaz.
Hence vb. XV. ploughland XIII unit of land assessment based on the area tillable by a team of eight oxen in a year. ploughshare XIV.