The Collaborative International Dictionary of English v.0.48:

kimono \ki*mo"no\ (k[i^]*m[=o]"n[=o]; Jap. k[i^]m"[=o]*n[=o]),
   n.; pl. -nos (k[i^]*m[=o]"n[=o]z). [Jap., article of
   clothing, fr. ki to wear + mono thing.]
   1. A kind of loose robe or gown tied with a sash, worn as a
      traditional outer garment by Japanese women and men. Women
      may wear it with a broad sash called an obi, having a
      large bow in the back. At present (1998), most Japanese
      wear it only at home or on ceremonial occasions,
      western-style clothing being more common in the workplace.
      [Webster 1913 Suppl. +PJC]

   2. A similar gown worn as a dressing gown by women of Western
      nations.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

kimono
    n 1: a loose robe; imitated from robes originally worn by
         Japanese