O.E. plog, ploh "plow, plowland (a measure of land)," possibly from Scand. (cf. O.N. plogr "plow"), from P.Gmc. *plogo- (cf. O.Fris. ploch, M.L.G. ploch, M.Du. ploech, O.H.G. pfluog). O.C.S. plugu, Lith. plugas "plow" are Germanic loan-words, as is probably L. plovus, plovum "plow," a word said by Pliny to be of Rhaetian origin. Replaced O.E. sulh, cognate with L. sulcus "furrow." As a name for the Big Dipper, it is recorded from 1513. The verb is first recorded c.1420. Plowshare is first recorded c.1380.