from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A wheel or portion of a wheel placed horizontally over the forward axle of a carriage to provide support and stability during turns.
  • noun A similar device over the rear axle or axles of a tractor or pickup truck, serving as a coupling for a semitrailer.
  • noun An additional wheel carried on a four-wheeled vehicle as a spare.
  • noun An extra and unnecessary person or thing.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun A type of trailer hitch, which consists of a horseshoe-shaped plate on a multi-directional pivot, with a locking pin to couple with the kingpin of a truck trailer.
  • noun A very large truck trailer; an 18-wheeler.
  • noun A very large trailer that is towed with a pickup truck.
  • noun idiomatic Anything superfluous or unnecessary.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a steering bearing that enables the front axle of a horse-drawn wagon to rotate
  • noun someone or something that is unwanted and unneeded
  • noun an extra car wheel and tire for a four-wheel vehicle


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