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.
lose one's temper (at someone or something)
Fig. to become angry at someone or something. Lisa lost her temper and began shouting at Bob. I hate to lose my temper at someone. I always end up feeling guilty.
lose one's temper
Also, lose it. Give way to violent anger, lose self-control. For example, When she found out what Ann had done, she lost her temper, or He arrived without that important check, and then I just lost it completely. The first term dates from the early 1800s; the second slangy locution dates from the mid-1900s.
keep/lose your ˈtemper (with somebody)
manage/fail to control your anger: You must learn to keep your temper.He loses his temper very quickly if you argue with him.