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:
hear of (someone or something)
Meaning:
to know about someone or something, to be familiar with someone or something
Example:
I have never heard of the singer.
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.