flap

1 of 2

noun

ˈflap 

1

: a stroke with something broad : slap

2

obsolete : something broad and flat used for striking

3

: something that is broad, limber, or flat and usually thin and that hangs loose or projects freely: such as

a

: a piece on a garment that hangs free

b

: a part of a book jacket that folds under the book's cover

c

: a piece of tissue partly severed from its place of origin for use in surgical grafting

d

: an extended part forming the closure (as of an envelope or carton)

4

: the motion of something broad and limber (such as a sail or wing)

5

: a movable auxiliary airfoil usually attached to an airplane wing's trailing edge to increase lift or drag see airplane illustration

6

a

: a state of excitement or agitation : tizzy, uproar

b

: something that generates an uproar

7

: a consonant (such as the sound \d\ in ladder and \t\ in latter) characterized by a single rapid contact of the tongue or lower lip against another point in the mouth

called also tap

flap

2 of 2

verb

flapped; flapping

transitive verb

1

: to beat with or as if with a flap

2

: to toss sharply : fling

3

: to move or cause to move in flaps

intransitive verb

1

: to sway loosely usually with a noise of striking and especially when moved by wind

2

a

: to beat or pulsate wings or something suggesting wings

b

: to progress by flapping

c

: to flutter ineffectively

3

: to talk foolishly and persistently

Synonyms

Noun

• frenzy
• rampage

Verb

• flutter

Examples of flap in a Sentence

Noun

She opened the tent flap and crawled outside.

the inside flap of a book's cover

a loose flap of skin

Verb

The breeze flapped the sails.

The flag flapped in the breeze.

The bird's wings were flapping.

Recent Examples on the Web

Noun

Underneath the slab of ribs is a flap of meat called the skirt, which is also trimmed off. —Susan Selasky, Freep.com, 4 July 2025

The soft style — shaped as a croissant with a rounded handle and signature secret pockets under the flap to hold essentials, such as lipstick, sunglasses, cash and a smartphone — made a return for fall 2025 as part of the collection that marked the Roman fashion house’s centennial this year. —Martino Carrera, Footwear News, 3 July 2025

Verb

One float depicted him as an outlaw, riding a motorcycle through a window to freedom; another showed his big ears flapping triumphantly in the wind. —David W. Brown, New Yorker, 5 July 2025

The moths were still able to flap their wings freely and turn in different directions. —Sarah Kuta, Smithsonian Magazine, 23 June 2025

Word History

Etymology

Noun

Middle English flappe

First Known Use

Noun

14th century, in the meaning defined at sense 1

Verb

14th century, in the meaning defined at transitive sense 1

Phrases Containing flap

• in a flap
• mud flap

Rhymes for flap

• app
• cap
• chap
• clap
• crap
• frap
• gap
• hap
• lap
• nap
• nappe
• pap

Kids Definition

flap

1 of 2 noun

ˈflap 

1

: slap entry 1 sense 1

2

: a broad, limber, or flat piece that hangs loose (as on a pocket or envelope)

3

: the motion or sound of a flap

4

: a movable part of an airplane wing that is attached to the trailing edge of the wing and that is used to increase lift or drag

flap

2 of 2 verb

flapped; flapping

1

: slap entry 2 sense 1a

2

: to move or cause to move with a beating motion

flapping its wings

Medical Definition

flap

noun

ˈflap 

: a piece of tissue partly severed from its place of origin for use in surgical grafting