The Collaborative International Dictionary of English v.0.48:

Tumbrel \Tum"brel\, Tumbril \Tum"bril\, n. [OF. tomberel, F.
   tombereau, fr. tomber to fall, to tumble; of Teutonic origin.
   Cf. Tumble.]
   1. A cucking stool for the punishment of scolds.
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   2. A rough cart. --Tusser. --Tatler.
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   3. (Mil.) A cart or carriage with two wheels, which
      accompanies troops or artillery, to convey the tools of
      pioneers, cartridges, and the like.
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   4. A kind of basket or cage of osiers, willows, or the like,
      to hold hay and other food for sheep. [Eng.]
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WordNet (r) 3.0 (2006):

tumbril
    n 1: a farm dumpcart for carrying dung; carts of this type were
         used to carry prisoners to the guillotine during the French
         Revolution [syn: tumbrel, tumbril]