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:
build up to (something)
Meaning:
to lead up to something
Example:
Things were building up to be a very serious problem.
List of common idioms, their meanings and examples of their usage in sentences
An idiom is defined as - a group of words in a fixed order that has a particular meaning that is different from the meanings of each word on its own.