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1. To begin to burn. Don't worry, the tinder will flare up eventually.
2. To begin to burn more intensely. The fire suddenly flared up and crackled even louder.
3. To suddenly worsen or intensify. My arthritis always seems to flare up at this time of year.
4. To suddenly lash out in anger. After I accidentally tapped that guy with my shopping cart, he just flared up and started screaming in my face!
5. To intensify into violence. This area is so unstable that war is liable to flare up at any moment.
1. Lit. [for something] to ignite and burn. The firewood flared up at last—four matches having been used.
2. Lit. [for a fire] to burn brightly again and expand rapidly. After burning quietly for a while, the fire suddenly flared up and made the room very bright.
3. Fig. [for a pain or medical condition] to get worse suddenly. My arthritis flares up during the damp weather.
4. Fig. [for a dispute] to break out or escalate into a battle. A war flared up in the Middle East. We can't send the whole army every time a dispute flares up.
5. and flare up at someone or something Fig. to lose one's temper at someone or something. I could tell by the way he flared up at me that he was not happy with what I had done. I didn't mean to flare up.
Suddenly become angry, as in She flared up at the slightest provocation. This metaphoric expression, dating from the mid-1800s, transfers a sudden burst of flame to sudden rage.
1. To begin to increase in intensity: My rash flared up when I went outdoors into the sunshine.
2. To express sudden, strong negative emotions, especially anger or hate: The store manager flared up when the employee started talking back.