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 flare-up in the tensions between the former bandmates comes as Hagar is about to resume his Best of All Words residency at the Park MGM in Las Vegas. — Andy Greene, Rolling Stone, 18 Sep. 2026

Air fresheners, perfumes, cleaning supplies and paint spark allergy flare-ups that can last for 10 days. — Maven Navarro, Fort Worth Star-Telegram, 18 Sep. 2026

Crews continue responding to new flare-ups across North Texas, and Turner said the region could remain active through the end of September and into early October. — Amelia Mugavero, CBS News, 17 Sep. 2026

Fires within the debris pile burned through the end of December 2001 with flare-ups in 2002. — ABC News, 11 Sep. 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