Flares up is a phrase that is used to describe an intense reaction or outburst. The crossword solutions for this phrase are ERUPTS (6 letters), BLAZES (6 letters), and SEESRED (7 letters). ERUPTS implies a sudden and violent release of energy, while BLAZES suggests a bright and powerful flame. SEESRED is an idiom that means to become extremely angry. All three words can be used to describe a situation in which someone flares up.