plural flaps
1
: a flat piece of material that is attached to something on one side and that can be easily moved
She opened the tent flap and crawled outside.
the inside flap of a book's cover
a loose flap of skin
2
: the movement or sound of something that is moving up and down or back and forth
the soft flap [=flapping] of the flag in the breeze
the steady flap [=beat] of the bird's wings
3
informal
a
: a state or situation in which many people are excited or upset
He was widely criticized during the recent flap [=uproar] about his controversial new book.
b
chiefly British
: a state in which someone is very upset
He got in a flap [=he became upset] over the delays in the schedule.
4
: a movable part of an airplane wing that can be raised or lowered and that is used to increase lift
flaps; flapped; flapping
: to move (something) up and down or back and forth
birds flapping their wings
The breeze flapped the sails.
The flag flapped in the breeze.
The bird's wings were flapping.
Cite this Entry
“Flap.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/flap. Accessed 6 Apr. 2026.
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