Idioms can be a powerful linguistic tool only when they are used in the right way in the right places.
Idiom:
keep cool
Meaning:
to stay calm
Example:
The police officers were trained to keep cool in difficult situations.
List of common idioms, their meanings and examples of their usage in sentences
An expression in the usage of a language that is peculiar to itself either in having a meaning that cannot be derived from the conjoined meanings of its elements or in its grammatically atypical use of words.