flare up in WordNet English dictionary

1. erupt or intensify suddenly
   "Unrest erupted in the country"; "Tempers flared at the meeting"; "The crowd irrupted into a burst of patriotism"
   erupt  irrupt  flare up  flare  break open  burst out 
   
2. ignite quickly and suddenly, especially after having died down
   "the fire flared up and died down once again"
   flare up