An idiom is defined as - a group of words whose meaning is different from the meanings of the individual words.
Idiom:
come back (into fashion)
Meaning:
to become popular again
Example:
Recently, bell-bottom pants have come back into fashion.
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.