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.
Idiom:
feed (someone) a line
Meaning:
to deceive someone
Example:
The man was feeding me a line about his plans to open the new restaurant.
List of common idioms, their meanings and examples of their usage in sentences
An idiom is a type of phrase or expression that has a meaning that can't be deciphered by defining the individual words.