In the culinary arts, there's pretty much a word for everything, even the little roasty bits left at the bottom of a pan where something has been cooked. Fond (pronounced "fahn"), from the French word for "bottom," is the word for those little roasty bits.
Because of how it is created, fond is concentrated flavor, and the technique for dislodging the fond from the bottom of the pan and incorporating into a sauce, is called deglazing.
The word fond is also the French word for stock. Fond blanc is a white stock, fond brun is brown stock, and fond de vegetal is vegetable stock.