v. i. 1. To burn till the fuel is exhausted; as, when the candle burned out the room was totally dark; the firefighters couldn't control the oil tank fire and had to let it burn out by itself. [ 1913 Webster +PJC ]
2. To stop functioning due to failure of some component caused by the heat of the electrical current used in its operation; -- of electrical devices. [ PJC ]
3. To become apathetic or depressed, and cease to function effectively, due to the fatigue and frustration of prolonged stress and overwork; -- of people; as, the stress in the bond market is so great that many traders burn out after only ten years on the job. [ PJC ]