PSEUDONYM
pseudonym, anonym, nom de guerre
(noun) a fictitious name used when the person performs a particular social role
Source: WordNet® 3.1
Etymology
Noun
pseudonym (plural pseudonyms)
A fictitious name, as those used by writers and movie stars.
Hyponyms
• (acting contexts): stage name
• (literary contexts): pen name, pen-name, nom de plume
• (military contexts): nom de guerre
• (another person's actual name adopted as a pseudonym): allonym
Coordinate terms
• alias, handle, moniker, nickname
Source: Wiktionary
Pseu"do*nym, n. Etym: [Cf. F. pseudonyme. See Pseudonymous.]
Definition: A fictitious name assumed for the time, as by an author; a pen
name. [Written also pseudonyme.]
Source: Webster’s Unabridged Dictionary 1913 Edition