Idioms
An idiom is a group of words, or in other words, a phrase that has a meaning other than its literal meaning of the words in it.
Idiom:
go off on a tangent
Meaning:
to suddenly change one's line of thought or course of action
Example:
The speaker suddenly went off on a tangent and began to speak about something totally different.
List of common idioms, their meanings and examples of their usage in sentences
An idiom is defined as - a group of words whose meaning is different from the meanings of the individual words.