What is "dumping car"

Dump \Dump\ (d[u^]mp), v. t. [imp. & p. p. Dumped; p. pr. & vb. n. Dumping.] [OE. dumpen to throw down, fall down, cf. Icel. dumpa to thump, Dan. dumpe to fall suddenly, rush, dial. Sw. dimpa to fall down plump. Cf. Dump sadness.]

1. To knock heavily; to stump. [Prov. Eng.]
   --Halliwell.

2. To put or throw down with more or less of violence; hence, to unload from a cart by tilting it; as, to dump sand, coal, etc. [U.S.]
   --Bartlett.

   Dumping car or Dumping cart, a railway car, or a cart, the body of which can be tilted to empty the contents; -- called also dump car, or dump cart.