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

People with digestive conditions that require a temporary low-fiber diet during flare-ups may also need to limit unhulled sesame seeds, since their fiber-rich outer hull can be difficult to tolerate. — Daryl Austin, USA Today, 12 Aug. 2026

Teams have been working to prevent flare-ups on the ground and with aerial operations, Nugraha said. — ABC News, 11 Aug. 2026

In the study, people taking azithromycin had a 17% lower risk of experiencing their first moderate or severe flare-up and 11% less flares one year later. — Helen Carefoot, Flow Space, 11 Aug. 2026

The flare-up has reached that scale in just over two months, surpassing the country’s last major Ebola epidemic, which spanned nearly two years between August 2018 and June 2020. — Nimi Princewill, CNN Money, 6 Aug. 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