Idioms
An idiom is a type of phrase or expression that has a meaning that can't be deciphered by defining the individual words.
Idiom:
hang back
Meaning:
to stay some distance behind someone or away from someone, to hesitate or be unwilling to do something
Example:
The man always hangs back when his boss asks for volunteers.
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.