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
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 popular China internet fund, the KraneShares CSI China Internet ETF (KWEB), is down more than 40% from its record in October amid ongoing concerns over AI valuations and trade ware flare-ups.
—
Oliver Renick,
CNBC,
1 July 2026
Lymph nodes cluster heavily in this area, and poor circulation through them can produce acne along the jaw and neck, dry or flaky skin, eczema flare-ups or unexplained rashes.
—
Allison Palmer,
Kansas City Star,
29 June 2026
Poor circulation there may also show up as dry or flaky skin, eczema flare-ups or unexplained rashes.
—
Allison Palmer,
Charlotte Observer,
29 June 2026
The United States and Iran late Sunday pulled back from their escalating attacks over the Strait of Hormuz, a flare-up that had tested a fragile ceasefire and called into question both sides’ desire to avoid a full return to battle.
—
Scott Peterson,
Christian Science Monitor,
29 June 2026
See All Example Sentences for flare-up
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Oliver Renick,
CNBC,
1 July 2026
Lymph nodes cluster heavily in this area, and poor circulation through them can produce acne along the jaw and neck, dry or flaky skin, eczema flare-ups or unexplained rashes.
—
Allison Palmer,
Kansas City Star,
29 June 2026
Poor circulation there may also show up as dry or flaky skin, eczema flare-ups or unexplained rashes.
—
Allison Palmer,
Charlotte Observer,
29 June 2026
The United States and Iran late Sunday pulled back from their escalating attacks over the Strait of Hormuz, a flare-up that had tested a fragile ceasefire and called into question both sides’ desire to avoid a full return to battle.
—
Scott Peterson,
Christian Science Monitor,
29 June 2026
See All Example Sentences for flare-up
Cite this Entry
“Flare-up.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/flare-up. Accessed 5 Jul. 2026.
Copy CitationMedical Definition
flare-up
noun
: a sudden appearance or worsening of the symptoms of a disease or condition
an asthmatic flare-up
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