Source : WordNet®

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