Deglazing
Deglazing means adding cold liquid to a hot mass to stop it cooking and to dissolve what has stuck to the base. In pastry the technique is applied above all to caramel: hot cream or purée goes in, the temperature drops sharply and caramelisation stops.
The moment is judged by the colour and smell of the caramel, which keeps darkening from residual heat for a while after it leaves the flame — so you deglaze slightly before the shade you want. Caramel taken too far turns bitter, and there is no correcting it.
The liquid goes in warmed and in stages: cold liquid causes violent boiling and spitting, and the caramel can seize into lumps. If it does, return the pan to low heat and warm it until the crystals dissolve.
In savoury cooking the same word describes lifting the browned layer from a pan with wine or stock to build a sauce.