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

Know your treatment options Plain dandruff and a more inflamed seborrheic dermatitis flare-up aren’t always easy to tell apart on your own, but the timeline is a good clue. — Ayren Jackson-Cannady, Allure, 20 Aug. 2026

After multiple flare-ups and suggestions of an imminent accord, there do not appear to be any concrete plans to end the 24-week war. — August 17, CBS News, 17 Aug. 2026

Dermatologist Toral Vaidya of MDCS Dermatology in New York told HuffPost that consistent exposure to dry air can dehydrate your skin, worsen sensitivity and trigger flare-ups of underlying conditions like eczema. — Samantha Agate, Sacbee.com, 17 Aug. 2026

In France, firefighters battling a wildfire in a pine forest in the southwestern Landes region faced no major flare-ups overnight, Landes Prefect Gilles Clavreul said. — Sylvie Corbet, Los Angeles Times, 16 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