lose (one's) temper
To become angered, enraged, or upset due to some provocation; to have an outburst upon losing one's patience. I'm usually a pretty calm person, but whenever I start driving, I find I lose my temper at the slightest inconvenience. When we were kids, my dad lost his temper a lot, but he's mellowed out since then.
Farlex Dictionary of Idioms. © 2024 Farlex, Inc, all rights reserved.