Nickname
Part of speech: verb
Definition: To give a nickname to (a person or thing).
Part of speech: noun
Definition: A familiar, invented given name for a person or thing used instead of the actual name of the person or thing. A kind of byname that describes a person by a characteristic of that person.
Example sentence: My feet ain't got nothing to do with my nickname, but when folks get it in their heads that a feller's got big feet, soon the feet start looking big.
Sobriquet
Part of speech: noun
Definition: A familiar name for a person (typically a shortened version of a person's given name).