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:
lean over backwards to (do something or help someone)
Meaning:
to do everything possible to do something or help someone
Example:
My cousin leaned over backwards to help my father when he was sick.
List of common idioms, their meanings and examples of their usage in sentences
An idiom is defined as - a group of words whose meaning is different from the meanings of the individual words.