Nickname (noun)

1. A name added to or substituted for the proper name of a person, place, or thing.
2. A familiar or humorous name given to a person or thing instead of or as well as the real name.

Origin:

Mid 16th century (denoting a name given in addition to the real name): from eke name.

Examples:

1. His nickname was "Robby" but his real name was Robert.
2. The city"s nickname was "The Big Apple".
3. The team"s nickname was "The Fighting Irish".
4. He acquired the nickname "Tiny" due to his small stature.
5. She was known by her nickname "Red" because of her red hair.