flare

1 of 2

noun

ˈfler 

1

: a fire or blaze of light used especially to signal, illuminate, or attract attention

also : a device or composition used to produce such a flare

The airport set flares to guide the landing plane at night.

2

a

: an unsteady glaring light

b

: solar flare

also : a sudden increase and decrease in the brightness of a star often amounting to a difference of several magnitudes (see magnitude sense 3)

3

a

: a sudden outburst (as of excitement or anger)

a flare of tempers in the courtroom

b

: flare-up sense 3

a flare of disease

4

a

: a spreading outward

also : a place or part that spreads

a skirt with a flare at the hem

b

: an area of skin flush

a flare of reddened skin

5

: light resulting from reflection (as between lens surfaces) or an effect of this light (such as a fogged or dense area in a photographic negative)

6

a

: a short pass in football thrown to a back who is running toward the sideline

b

: a weakly hit fly ball in baseball

a flare into short right field

7

flares plural : pants that flare toward the bottom

flare

2 of 2

verb

flared; flaring

intransitive verb

1

a

: to burn with an unsteady flame

b

: to stream in the wind

2

a

: to shine with a sudden light

A match flared in the darkness.

b(1)

: to become suddenly excited or angry

tempers flared

—usually used with up

They flare up at each other, and Patsy … gives as good as she gets.

—Pauline Kael

(2)

: to break out or intensify usually suddenly or violently

a dispute that flared into a military conflict

—often used with up

A sudden pain flared up in his middle and stopped him at the sink.

—Gloria Naylor

c

: to express strong emotion (such as anger)

Scotty and I flared and raged …

—Jack London

3

: to open or spread outward

The pants flare at the bottom.

The bull's nostrils flared.

transitive verb

1

: to display conspicuously

flaring her scarf to attract attention

2

: to cause to flare

breezes flaring the candle

3

: to signal with a flare or by flaring

4

: to burn (a jet of waste gas) in the open air

Synonyms of flare

Noun

• flurry
• burst
• outburst
• flutter
• outbreak

Verb

• glow
• burn
• glare
• flame
• flash
• blaze
• gleam

Examples of flare in a Sentence

Noun

the sudden flare of the match

When the crew saw flares, they knew the other ship was in trouble.

Verb

pants that flare at the bottom

The bull flared its nostrils.

Recent Examples on the Web

Noun

These outbursts send radiation and charged particles hurling into space and can disrupt communications on Earth if the flare erupts from an Earth-facing sunspot. —Daisy Dobrijevic, Space.com, 10 Nov. 2025

While the first show had some minor issues, including a fan launching flares into the crowd, the tour’s reception has been overwhelmingly positive. —Jessica Lynch, Billboard, 10 Nov. 2025

Verb

This crewneck cardigan is one of the most timeless and versatile pieces on this list, with subtle ribbing and flared sleeves that add a bit of volume to the otherwise figure-skimming sweater. —Sophie Dodd, Travel + Leisure, 11 Nov. 2025

On November 12, the Last Quarter Moon in Leo flares up the tension between your public self and your private desires. —Dossé-Via Trenou, Refinery29, 9 Nov. 2025

Word History

Etymology

Noun and Verb

origin unknown

First Known Use

Noun

1580, in the meaning defined at sense 1a

Verb

1616, in the meaning defined at intransitive sense 1a

Phrases Containing flare

• flare-up
• solar flare
• tempers flare

Rhymes for flare

• air
• ayre
• bahr
• bare
• blare
• care
• chair
• claire
• ere
• err
• eyre
• fair

Kids Definition

flare

1 of 2 noun

ˈfla(ə)r 

ˈfle(ə)r

1

: a fire or blaze of light used to signal, light up something, or attract attention

also : a device or material that produces such a flare

2

: an unsteady glaring light

3

: flare-up

4

: a spreading outward

also : a place or part that spreads

5

plural : bell-bottom trousers

flare

2 of 2 verb

flared; flaring

1

: to burn with an unsteady flame

2

a

: to shine or blaze suddenly

b

: to become suddenly excited or angry

flare up

3

: to open or spread outward

pants that flare at the bottom

Medical Definition

flare

1 of 2 intransitive verb

ˈfla(ə)r, ˈfle(ə)r 

flared; flaring

: to break out or intensify rapidly : become suddenly worse or more painful

—often used with up

your gallstones flare up

—W. A. Nolen

flare

2 of 2 noun

1

: flare-up

Without effective urate lowering, many such patients progress to severe chronic gout characterized by frequent arthritic flares …

—John S. Sundy et al., The Journal of the American Medical Association

2

: an area of skin flush resulting from and spreading out from a local center of vascular dilation and hyperemia

urticarial flare

3

: a cloudy or smoky appearance of the fluid of the anterior chamber of the eye that is seen when a beam of light (as from a slit lamp) is passed through it and that is caused by the presence of floating protein material in the fluid which is a symptom of inflammation

Flare means that we can actually see the beam of light from the slit lamp traveling through the aqueous humor. This is similar to being able to see the beam of light coming from a movie projector in a dusty room.

—Jay B. Lavine, The Eye Care Sourcebook

called also aqueous flare