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

Speaking to the theatrical experience, Spielberg made a brief allusion to the flare-up around comments by Timothée Chalamet regarding the popularity of opera and ballet in relation to the movies. —Los Angeles Times, 13 Mar. 2026

Kilauea is among the world’s most active volcanoes, with sporadic flare-ups since December 2024. —Marc Ramirez, USA Today, 10 Mar. 2026

Since stress can trigger acne flare-ups and hair shedding, supporting the body’s stress balance may help minimize these effects. —Amanda Le, InStyle, 7 Mar. 2026

Previous flare-ups have calmed after days of fighting, and mediation by foreign governments including Saudi Arabia and Turkey. —Sophia Saifi, CNN Money, 27 Feb. 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