flare up

Verb

• erupt or intensify suddenly
  • Unrest erupted in the country
    
  • Tempers flared at the meeting
    
  • The crowd irrupted into a burst of patriotism
    

• ignite quickly and suddenly, especially after having died down
  • the fire flared up and died down once again
    

Related words

• Synonyms: 
  erupt , irrupt , flare , break open , burst out