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:
get off one's butt
Meaning:
to get busy, to start working
Example:
My friend should get off his butt and try to find a job.
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.