IPA: /ˈpriːhiːt/
KK: /priˈhit/
To heat something, like an oven, before using it for cooking.
Please preheat the oven to 350 degrees before baking the cake.
Past: preheated
Past Participle: preheated
Preheat → It is formed from "pre-" (meaning before) and "heat" (from Old English "hætu", meaning warmth or heat). The word "preheat" means to heat something before it is used or cooked.
Think of heating something 'before' ('pre-') it is used — that's why preheat means to warm it up in advance.