An idiom is a group of words, or in other words, a phrase that has a meaning other than its literal meaning of the words in it.
Idiom:
shrug (something) off or shrug off (something)
Meaning:
to not be bothered or hurt by something, to disregard something
Example:
The girl says mean things but we always shrug off her comments.
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.