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

The side walls and the top flap zip open, and the mesh walls have tiny curtains that roll up or Velcro closed to give your pet some peace and quiet. —Olivia Young, Travel + Leisure, 11 Oct. 2025

But where barrel jeans play with proportions and cuts, these pants are more about doohickeys and thingamabobs, straps, flaps, and pulleys. —Sam Reed, Glamour, 10 Oct. 2025

Verb

Moments later, the monarch began to flap its wings and crawl onto Bendicksen’s hand. —Aamir Khollam, Interesting Engineering, 11 Oct. 2025

But its appeal can’t be divorced from the romance of its history, which properly began in the 19th century when English polo players began wearing oxford shirts as their preferred uniform, complete with collars that buttoned against the body to prevent their points from flapping in the wind. —Eric Twardzik, Robb Report, 6 Oct. 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