The Collaborative International Dictionary of English v.0.48:

Foul \Foul\, v. t. [imp. & p. p. Fouled; p. pr. & vb. n.
   Fouling.]
   1. To make filthy; to defile; to daub; to dirty; to soil; as,
      to foul the face or hands with mire.
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   2. (Mil.) To incrust (the bore of a gun) with burnt powder in
      the process of firing.
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   3. To cover (a ship's bottom) with anything that impered its
      sailing; as, a bottom fouled with barnacles.
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   4. To entangle, so as to impede motion; as, to foul a rope or
      cable in paying it out; to come into collision with; as,
      one boat fouled the other in a race.
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