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:
less than pleased
Meaning:
not pleased
Example:
My father was less than pleased when I returned his car late last night.
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 different from the literal meaning of the words in it.