I .
burn out | ˌburn itself ˈout
( of a fire ) to stop burning because there is nothing more to burn :
The fire had burnt (itself) out before the fire engines arrived.
II .
burn out | ˌburn sth ↔ ˈout
to stop working or to make sth stop working because it gets too hot or is used too much :
The clutch has burnt out.
III .
burn out | ˌburn yourself / sb ˈout
to become extremely tired or sick by working too hard over a period of time :
If he doesn't stop working so hard, he'll burn himself out.
By the age of 25 she was completely burned out and retired from the sport.
—related noun burnout