flap
One way to use the word “flap” is as a verb. Animals that fly, especially birds, flap their wings in order to move through the air.
| A bird flies when it flaps its wings. |  |
|---|---|
| In the evening, you can see bats quickly flapping their wings. |  |
When the word “flap” is used as a noun, it refers to that part of a box or an envelope that folds and seals whatever is inside.
| The flaps on a box look a little like wings. |  |
|---|---|
| He’s licking the seal on the flap of the envelope. |  |
There are some other ways to use the word “flap.”
A flag flaps in the wind. This flag is flapping in the wind.
Pancakes are sometimes referred to as flapjacks. He’s sitting behind a stack of flapjacks.