1. a sudden, violent outburst or eruption of something (such as anger, violence, or conflict)
Usage: commonly used in social and interpersonal contexts
2. a sudden worsening or recurrence of a disease or medical condition
Usage: medical/health context

Examples

• A flare-up of violence erupted in the city after the controversial decision.
• Her asthma flare-up forced her to use her inhaler several times during the day.
• The argument was just a minor flare-up between old friends.
• The patient experienced a flare-up of arthritis pain during cold weather.
• A flare-up of tensions between the two nations threatened the peace agreement.
• His allergies caused a flare-up that lasted for a week.