pseudonym
Concise Oxford English Dictionary © 2008 Oxford University Press:
pseudonym /ˈs(j)uːdənɪm/
▶noun a fictitious name, especially one used by an author.
– origin C19: from Fr. pseudonyme, from Gk pseudōnymos, from pseudēs ‘false’ + onoma ‘name’.
'pseudonym' also found in these Oxford entries:

