Flap Names the Motion, the Sound and the Panic
To flap is to move up and down. The word covers wings, hinged panels and a state of agitation.
To flap is to move up and down or from side to side; a flap is a hinged or hanging piece. The word is imitative of the noise, and the senses spread from there: a bird flaps, a tent flap flaps in the wind, and being *in a flap* means agitated, as though fluttering. On an aircraft, flaps are hinged panels on the wing that increase lift at low speed, which is what lets a large aeroplane land on a runway of practical length.
- To move up and down. *Wings flapping.*
- A hinged piece. *A tent flap.*
- A state of agitation. *In a flap.*
- An aircraft control surface. *Lower the flaps.*
- Imitative. *From the 1300s.*
Word forms
| Form | Word | Example |
|---|---|---|
| Verb | flap | Flapping. |
| Noun | flap | A flap. |
| Plural | flaps | Flaps. |
| Past | flapped | Flapped. |
| Related | flutter | To flutter. |
- The sail flapped loudly.Motion.
- She lifted the tent flap.Panel.
- He was in a terrible flap.Agitation.
What aircraft flaps do
- They extend and angle down from the trailing edge of the wing
- This increases lift at low speed
- It also increases drag, which helps an aircraft slow down
- Without them landing speeds would be far higher
- Runways could not be the length they are
Middle English, imitative of the sound of something striking loosely, recorded from the 1300s.
What do aircraft flaps do?
They increase lift and drag at low speed, letting an aeroplane approach and land more slowly on a runway of practical length.
Where does in a flap come from?
From the image of agitated fluttering, the same motion as a bird's wings or a loose sail.