plough

n. & v. (esp. US plow)
—n.
1 an implement with a cutting blade fixed in a frame drawn by a tractor or by horses, for cutting furrows in the soil and turning it up.
2 an implement resembling this and having a comparable function (snowplough).
3 ploughed land.
4 (the Plough) the constellation Ursa Major or its seven bright stars.
—v.
1 tr. (also absol.) turn up (the earth) with a plough, esp. before sowing.
2 tr. (foll. by out, up, down, etc.) turn or extract (roots, weeds, etc.) with a plough.
3 tr. furrow or scratch (a surface) as if with a plough.
4 tr. produce (a furrow or line) in this way.
5 intr. (foll. by through) advance laboriously, esp. through work, a book, etc.
6 intr. (foll. by through, into) move like a plough violently.
7 intr. & tr. Brit. colloq. fail in an examination.
Phrases and idioms:
plough back
1 plough (grass etc.) into the soil to enrich it.
2 reinvest (profits) in the business producing them. Plough Monday the first Monday after the Epiphany. put one's hand to the plough undertake a task (Luke 9:62).
Derivatives:
ploughable adj. plougher n.
Etymology: OE ploh f. ON ploacutegr f. Gmc