The language peculiar to a people or to a district, community, or class
Idiom:
to put it mildly
Meaning:
to understate something, to say something politely
Example:
To put it mildly, the food at the restaurant was the worst that I have ever tasted.
List of common idioms, their meanings and examples of their usage in sentences
An expression in the usage of a language that is peculiar to itself either in having a meaning that cannot be derived from the conjoined meanings of its elements or in its grammatically atypical use of words.