handle — a part of a thing made specifically to be grasped or held by the hand.
alias — An alias is a false name, especially one used by a criminal.
nickname — a name added to or substituted for the proper name of a person, place, etc., as in affection, ridicule, or familiarity: He has always loathed his nickname of “Whizzer.”.
nom de guerre — an assumed name, as one under which a person fights, paints, writes, etc.; pseudonym.
pen name — a pseudonym used by an author; nom de plume.
pseudonym — a fictitious name used by an author to conceal his or her identity; pen name. Compare allonym (def 1).
aka — aka is an abbreviation for 'also known as'. aka is used especially when referring to someone's nickname or stage name.
allonym — a name, often one of historical significance or that of another person, assumed by a person, esp an author
