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:
save (something) for a rainy day
Meaning:
to save something (eg. money) for the future
Example:
I plan to save some money for a rainy day.
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