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:
zero hour
Meaning:
the exact time when an attack or other military action will start
Example:
The air force planes waited until zero hour in order to begin their bombing mission.
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.