Idioms
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.
Idiom:
off duty
Meaning:
not working
Example:
The police officer was off duty when he saw the bank robbery.
List of common idioms, their meanings and examples of their usage in sentences
A group of words which have a different meaning when used together from the one they would have if you took the meaning of each word separately.