To cook food by heating in an oven or over a fire without covering, resulting in a crisp, possibly even slightly charred appearance.
to roast meat on a spit
To cook by surrounding with hot embers, ashes, sand, etc.
to roast a potato in ashes
To process by drying through exposure to sun or artificial heat
Coffee beans need roasting before use.
To heat to excess; to heat violently; to burn.
To admonish someone vigorously
I’m late home for the fourth time this week; my mate will really roast me this time.
To subject to bantering, severely criticize, sometimes as a comedy routine.
The class clown enjoys being roasted by mates as well as staff.
To dissipate by heat the volatile parts of, as ores.