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

Global oil prices have shot back up to $100 a barrel amid a flare-up in the US and Israel’s war with Iran. — Alicia Wallace, CNN Money, 23 July 2026

However, this period was not tension-free, with occasional flare-ups of hostilities along the border. — Encyclopedia Britannica, 22 July 2026

The flare-up complicates a week Manila had hoped would showcase its ASEAN chairmanship. — Anniek Bao, CNBC, 21 July 2026

The flare-up came in the eighth inning of an eventual 8-5 Yankees win. — Brendan Kuty, New York Times, 21 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