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:
stir up a hornet's nest
Meaning:
to make many people angry or dislike something, to provoke your critics
Example:
The man stirred up a hornet`s nest when he began to complain about the bonus system at his company.
List of common idioms, their meanings and examples of their usage in sentences
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.