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.
Idiom:
(not) move a muscle
Meaning:
to not move even a small amount
Example:
The doctor told me not to move a muscle when he was fixing my leg.
List of common idioms, their meanings and examples of their usage in sentences
An idiom is a widely used saying or expression containing a figurative meaning that differs from the phrase's literal meaning.