1. lose one's temper; get really angry
going to blow a fuse
A fuse is a circuit breaker used to protect a circuit in electrical components. If a 'fuse is blown' it means the fuse overloads the circuit causing the fuse to break. If a person 'blows a fuse' it refers to them losing their temper or becoming enraged: "My mother is going to blow a fuse when she finds out we broke the vase!" This is an informal phrase you can hear in lots of different situations. Similar to 'lose the head' and 'blow a gasket'.