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:
walk a tightrope
Meaning:
to be in a situation where you must be very cautious
Example:
The Prime Minister is walking a tightrope regarding the international trade deal.
List of common idioms, their meanings and examples of their usage in sentences
Idioms can be a powerful linguistic tool only when they are used in the right way in the right places.