nick·name 
(nĭknām′)
(nĭknām′)n.
1. A descriptive name added to or replacing the actual name of a person, place, or thing.
2. A familiar or shortened form of a proper name.
tr.v. nick·named, nick·nam·ing, nick·names
1. To give a nickname to.
2. Archaic To call by an incorrect name; misname.
[Middle English neke name, from a neke name, alteration of an eke name : eke, addition (from Old English ēaca; see aug- in the Appendix of Indo-European roots) + name, name; see NAME.]
nicknam′er n.