The Collaborative International Dictionary of English v.0.48:

Rub \Rub\, v. i.
   1. To move along the surface of a body with pressure; to
      grate; as, a wheel rubs against the gatepost.
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   2. To fret; to chafe; as, to rub upon a sore.
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   3. To move or pass with difficulty; as, to rub through woods,
      as huntsmen; to rub through the world.
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   To rub along or on, to go on with difficulty; as, they
      manage, with strict economy, to rub along. [Colloq.]
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