If a disease or injury flares up, it suddenly returns or becomes painful again. Students often find that their acne flares up before and during exams. see also flare 2, 3, flare-up
{i} sudden outburst of anger; sudden intensification; sudden bursting into flame; excitement, enthusiasm
Clumps of fuel or single trees that are consumed by fire rapidly and then die down, and do not constitute spread through the crowns
If there is a flare-up of violence or of an illness, it suddenly starts or gets worse. There's been a flare-up of violence in South Africa
Any sudden acceleration of fire spread or intensification of a fire Unlike a blow-up, a flare-up lasts a relatively short time and does not radically change control plans
Any sudden acceleration of fire spread or intensification of the fire or a part of the fire Unlike blow-up, a flare-up is of relatively short duration and does not radically change existing control plans
Any sudden acceleration of fire spread or intensification of the fire Unlike blowup, a flare-up is of relatively short duration and does not radically change existing control plans
Any sudden acceleration in rate of spread or intensification of the fire Unlike blowup, a flare-up is of relatively short duration and does not radically change existing control plans