Source : Webster's Revised Unabridged Dictionary (1913)

Viceroy \Vice"roy\, n. [F. vice-roi; pref. vice- in the place of
   (L. vice) + roi a king, L. rex. See {Vice}, prep. and Royal.]
   1. The governor of a country or province who rules in the
      name of the sovereign with regal authority, as the king's
      substitute; as, the viceroy of India.

   2. (Zo["o]l.) A large and handsome American butterfly
      ({Basilarchia, or Limenitis, archippus}). Its wings are
      orange-red, with black lines along the nervures and a row
      of white spots along the outer margins. The larv[ae] feed
      on willow, poplar, and apple trees.