al·lo·nym 
(ălə-nĭm′)
(ălə-nĭm′)n.
The name of a person, usually a historical person, assumed by a writer.
[French allonyme : Greek allos, other; see ALLO- + Greek onoma, name; see n-men- in the Appendix of Indo-European roots.]
al·lony·mous (ə-lŏnə-məs) adj.
al·lony·mous·ly adv.