The Collaborative International Dictionary of English v.0.48:

Tram \Tram\, n. [Prov. E. tram a coal wagon, the shaft of a cart
   or carriage, a beam or bar; probably of Scand, origin; cf.
   OSw. tr[*a]m, trum, a beam, OD. drom, Prov. & OHG. tram.]
   1. A four-wheeled truck running on rails, and used in a mine,
      as for carrying coal or ore.
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   2. The shaft of a cart. [Prov. Eng.] --De Quincey.
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   3. One of the rails of a tramway.
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   4. A car on a horse railroad. [Eng.]
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   Tram car, a car made to run on a tramway, especially a
      street railway car.

   Tram plate, a flat piece of iron laid down as a rail.

   Tram pot (Milling), the step and support for the lower end
      of the spindle of a millstone.
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