Epithet

Epithet is a name given to someone or something based on their quality or characteristic. For example, Richard the Lionheart, where 'Lionheart' is an epithet for Richard (1157 – 1199), the king of England.

Another example can be taken from Hindu mythology, where the god Vishnu is known by thousand names in the text called "Vishnu Sahasranama", where each name is an epithet based on the characteristic of the god Vishnu, such as Hari means who takes away all sins or sorrows of the material world.

It should be noted that an epithet may also refer to the evil characteristics or quality, such as Satan is called 'the Devil' in New Testament. Satan is personal name of the spiritual being who revolted against the God, and hence called the Devil.

In Grammar, when an epithet is used as defining word after a noun we don't use (,) in between. Therefore, we write 'Alexander the Great'. Writing 'Alexander, the Great' will be wrong.