The Collaborative International Dictionary of English v.0.48:

Rug \Rug\, n. [Cf. Sw. rugg entanglend hair, ruggig rugged,
   shaggy, probably akin to E. rough. See Rough, a.]
   1. A kind of coarse, heavy frieze, formerly used for
      garments.
      [1913 Webster]

            They spin the choicest rug in Ireland. A friend of
            mine . . . repaired to Paris Garden clad in one of
            these Waterford rugs. The mastiffs, . . . deeming he
            had been a bear, would fain have baited him.
                                                  --Holinshed.
      [1913 Webster]

   2. A piece of thick, nappy fabric, commonly made of wool, --
      used for various purposes, as for covering and ornamenting
      part of a bare floor, for hanging in a doorway as a
      poti[`e]re, for protecting a portion of carpet, for a wrap
      to protect the legs from cold, etc.
      [1913 Webster]

   3. A rough, woolly, or shaggy dog.
      [1913 Webster]

   Rug gown, a gown made of rug, of or coarse, shaggy cloth.
      --B. Johnson.
      [1913 Webster]