steam upverb

• 1

  To become steamy.

• 2

  To become coated with condensation.

  • The bathroom mirror steamed up when he opened the shower door.
  • The large plateglass window, from which I had an excellent view of the countryside the following day, was prevented from steaming up by a de-misting device.
• 3

  To bring (a steam boiler) up to working steam pressure: to build up a head of steam inside (a boiler).

  • It takes about an hour to steam up the locomotive.
• 4

  to build up a head of steam.

  • Engine 99 had been steaming up since 21:00.
  • "The master of the Nan-Shan [...] desired Mr. Rout to have steam up to-morrow afternoon at one o'clock sharp."
• 5

  To cook by steaming.

  • I'll steam up a bunch of dumplings.