flap

verb

flapped; flapping

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

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

Synonyms of flap

• flutter

Examples of flap in a Sentence

The breeze flapped the sails.

The flag flapped in the breeze.

The bird's wings were flapping.

Recent Examples on the Web

When a hummingbird hovers, their wings can flap up to 70 times per second, according to the Audubon Society! —Ray Petelin, CBS News, 6 June 2026

Once on the tree limb, the young birds can flap their wings, jump, and then land on a lower branch or back in their nest. —Laura Baisas, Popular Science, 4 June 2026

The slot formerly occupied by a performance from the Commodores will now be filled with the sound of a lone Gadsden flag flapping on its pole. —Alexandra Petri, The Atlantic, 3 June 2026

The fathers, faces ruddy, prayed in Latin for her soul, black robes flapping in the wind. —Literary Hub, 26 May 2026

Word History

First Known Use

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