Preheat (verb)

1. To heat something before using it.
2. To heat an oven or other heating device before using it to cook something.

Origin:

From pre- + heat.

Examples:

1. Preheat the oven to 350 degrees before baking the cake.
2. The recipe calls for preheating the skillet before adding the vegetables.
3. She preheated the water for tea before adding the tea leaves.
4. It is important to preheat the kiln before firing the pottery.
5. The metal should be preheated before welding.