rhizoverbBeta
DictionaryflapAttached piece
noun / verb

flap

FLAP/flæp/

A loose repeated swinging movement.

The towels flap on the clothesline in the afternoon breeze.

A plain canvas bag has a broad flat top flap lifted, clearly attached along one edge and ready to fold over its opening.
Etymology
flapMiddle Englishblow, slap

Middle English flappe meant a blow or slap, probably echoing its sound. The hanging-piece sense probably developed anew from the related verb meaning to swing loosely, connecting the movable piece with its motion.

In context

Osmosis from Elsevier5:22
pneumothorax is when there's a flap of tissue creating a one-way valve and it can allow pressure to build up over time that can press against nearby organs like the heart
Pneumothorax - causes, symptoms, diagnosis, treatment, pathology

More examples

  • The duck flaps its wings to shake off water.
  • Loose straps flapped against his backpack as he ran.
  • The steady flap of the awning keeps me awake.

Forms

flap · flaps · flapped · flapping

Similar words

flutter
Suggests lighter, quicker movements, often with less regularity.
swing
Emphasizes back-and-forth movement without necessarily suggesting looseness or repeated beating.