Define an idiomatic expression in simple words and uses example?

Answer 1

Idiomatic expressions are hard to understand literally by definition!

An idiomatic expression is a phrase whose meaning cannot be understood just by looking at the words in a dictionary.

Idiomatic expressions are colloquial (not a simple word, I know) - this means that they only have meaning to one specific culture. In even simpler terms - they are expressions that only a native speaker of the language understands, or someone who lives in that place.

Here are a few examples -

Break a leg!

This means good luck! But if you just read the words - break. a. leg. there is no way you'd ever know that that means good luck.

It's a piece of cake!

This means it is really easy. But if you just think about what a piece of cakes means, you would never know that. Cake is delicious, but doesn't have anything to do with being easy!

Answer 2

Let's add some more idiomatic expressions!

Idiomatic expressions rely on cultural context, so, using words that have innuendo and double meaning can help too.

"Down in the dumps" - feeling sad or lethargic. The dump is another word for the garbage pit, so its a play on feeling like trash.