A dictionary says plough means to form furrows with a plow, so I thought those who got ploughed in sports had deep cuts. However, my understanding might be a little strange in the following context (Harry Potter 4 [US Version]: p.108) , because he hit the ground. What kind and degree of injury did he get when he got ploughed? Would you use ‘get ploughed’ in common sports, I mean, non-magical sports?
(The sport’s players are flying on their brooms. Two of them are diving for a small ball.)
at the very last second, Viktor Krum pulled out of the dive and spiraled off. Lynch, however, hit the ground with a dull thud that could be heard throughout the stadium. A huge groan rose from the Irish seats.
(Then a spectator, Charlie, says)
”He’ll be okay, he only got ploughed!” Charlie said reassuringly to Ginny, who was hanging over the side of the box, looking horror-struck. [bold font is mine]
Side Note: I think ‘only’ means that it’s easy to recover by magic. So I guess ‘get ploughed’ causes serious injury in our world.
Best Answer
I take the "idiom" behind Charlie's usage to be derived, as onomatomaniak says, from the agricultural plough, with the full meaning of the expression intended to be something like "he only got (tricked into playing the part of a plough)"; i.e. because of Krum's maneuver, Lynch ran into the ground and dug up a big furrow of dirt just like a plough does.
I could see this sort of usage in, for example, American-style football if a player gets tackled while running and the tackler lands on top of him, essentially pushing the tackled player into the field as he slides to a stop. (Although causing actual damage to the field is rather unlikely, with the predominance of astroturf and other artificial surfaces.) The 'ploughed' player in this situation would probably have some abrasions and contusions, and possibly some blunt-force trauma from impacting the ground too hard if he didn't have adequate protective gear (football players are well-armored; Quidditch players, not so much).