What is the meaning of flat as a pancake?

"Flat as a pancake" is a simile that describes something as being extremely flat.

It's used to emphasize the lack of any significant thickness or height. For example:

* "The tire was flat as a pancake after hitting the curb."

* "The dough spread out flat as a pancake on the baking sheet."

* "The cat slept flat as a pancake on the rug."

The comparison to a pancake, which is known for its thin, flat shape, helps to create a vivid image in the listener's mind.