Flare up and Start up

Flare up verb - To become very angry.

Start up and flare up are semantically related in set on fire topic. In some cases you can use "Start up" instead a verb "Flare up".

Start up verb - Get going or set in motion.

Flare up and start up are semantically related in burn topic. Sometimes you can use "Flare up" instead a verb "Start up", if it concerns topics such as set on fire, kindle.