flare-up

noun

ˈfler-ˌəp 

1

: a sudden outburst or intensification

a flare-up of hostilities

2

: a sudden bursting (as of a smoldering fire) into flame or light

a danger of flare-ups

3

: a sudden appearance or worsening of the symptoms of a disease or condition

an asthmatic flare-up

Synonyms of flare-up

• flurry
• burst
• outburst
• outbreak
• flare

Examples of flare-up in a Sentence

took medication to prevent a flare-up of her asthma

there's no need for an angry flare-up, as we'll take care of the problem immediately

Recent Examples on the Web

The accident caps a chaotic Giants season marked by social-media flare-ups, on-field insubordination and a Pride Night uniform dispute. — Steve Henson, Los Angeles Times, 31 July 2026

On Thursday, the team agreed to a one-year deal with Deebo Samuel, a longtime member of their offense, who will likely slip into his familiar Z receiver position after a flare-up of Ricky Pearsall’s recurring knee injury. — Matt Barrows, New York Times, 31 July 2026

But the new flare-up saw oil prices surge again, with the international benchmark Brent crude oil hovering around $90 a barrel early Thursday. — Chantal Da Silva, NBC news, 30 July 2026

Tua Tagovailoa, held out of Wednesday’s practice because of a back injury flare-up, threw off to the side. — Daniel Flick, AJC.com, 30 July 2026

Word History

First Known Use

1839, in the meaning defined at sense 1

Rhymes for flare-up

• buttercup
• backup
• blowup
• breakup
• buildup
• checkup
• cleanup
• holdup
• hookup
• lineup
• lockup
• makeup

Kids Definition

flare-up

noun

ˈfla(ə)r-ˌəp, 

ˈfle(ə)r-

: a sudden burst (as of flame or anger)

Medical Definition

flare-up

noun

-ˌəp 

: a sudden appearance or worsening of the symptoms of a disease or condition

an asthmatic flare-up