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:
to a great extent
Meaning:
mainly, largely
Example:
To a great extent, everybody in the town has been informed of the new parking regulations.
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.