flop sweat

Etymology
From.

Noun

 * 1)  Sweat due to nervousness, especially fear of failure.
 * 2) * 15 March 1947, Bill Smith, "Night Club Reviews", Billboard page 36:
 * Billy Vine, covered with flop sweat, started so-so, but in a few minutes he had them.
 * 1)  Panic or anxiety about possible failure.