What does the idiom lost his temper mean?

The idiom "lost his temper" means someone became angry or out of control emotionally. It implies a sudden and intense outburst of frustration, rage, or irritation.

Here are some examples of how it's used:

* "When his car wouldn't start, John lost his temper and started kicking the tires."

* "She lost her temper when she realized her phone was stolen."

* "The teacher lost his temper after the students started talking during the exam."

Essentially, it indicates a person's inability to control their emotions in the face of a stressful or frustrating situation.