1A lingering burning sensation. In later use especially: a warm sensation in the mouth or throat caused by hot or spicy food or strong alcoholic drink.
2Burning that takes place after some event; specifically combustion after the removal or cessation of a flame.
3A temporary increase in a person's metabolic rate following a period of exercise.
Early 20th century; earliest use found in Boston Medical and Surgical Journal. From after- + burn.