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:
let on
Meaning:
to try to make people believe something, to pretend something
Example:
The man tried to let on that he did not want the job but actually he did.
List of common idioms, their meanings and examples of their usage in sentences
The language peculiar to a people or to a district, community, or class