To become physically or emotionally exhausted, especially as a result of prolonged stress or overwork. After working 70-hour weeks for months, she finally burned out and had to take a leave of absence.
To stop functioning due to overheating or overuse, often referring to electrical devices or engines. The motor burned out after running continuously for several hours.
To extinguish a fire by allowing it to consume all available fuel. The campfire burned out overnight, leaving only ashes in the morning.