Webster's Revised Unabridged Dictionary · 1913

Superheat

Superheat , transitive verb

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.
3.
To heat (a liquid) above its boiling point without converting it into vapor.

Superheat , noun

The increase of temperature communicated to steam by superheating it.