Verb
To become steamy.
To become coated with condensation. To fog up.
The bathroom mirror steamed up when he opened the shower door.
To bring (a steam boiler) up to working steam pressure.
It takes about an hour to steam up the locomotive.
The German Emperor is ageing me; he is like a battleship with steam up and screws going, but with no rudder, and he will run into something some day and cause a catastrophe. Edward Grey, 1st Viscount Grey of Fallodon
If your baby has a hard time feeding because of a stuffy nose, turn on the shower to steam up the bathroom and feed her there. Source: Internet
The windows steam up and the house smells like a storm. Source: Internet
This passionate pose will really steam up your bathroom mirror. Source: Internet