Source : Webster's Revised Unabridged Dictionary (1913)

Superheat \Su`per*heat"\, v. t. [imp. & p. p. {Superheated}; p.
   pr. & vb. n. {Superheating}.]
   1. To heat too much, to overheat; as, to superheat an oven.

   2. (Steam Engine) To heat, as steam, apart from contact with
      water, until it resembles a perfect gas.