ignite quickly and suddenly, especially after having died down;
"the fire flared up and died down once again"
erupt or intensify suddenly;
"Unrest erupted in the country"
"Tempers flared at the meeting"
"The crowd irrupted into a burst of patriotism"
- This was done, and a flame flared up but it was outshone by the fire from the altar.
- This dormant volcano suddenly fired up.
- In a sudden burst of anger, the man tore up everything within reach.
- flare up 骤燃