Idioms
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.
Idiom:
gray area
Meaning:
something difficult to define or put into a particular category, something that is not clear
Example:
Some of the legal issues were in a gray area.
List of common idioms, their meanings and examples of their usage in sentences
Idioms are phrases which cannot be understood simply by looking at the meaning of the individual words in the phrase.