pen name

from The American Heritage® Dictionary of the English Language, 4th Edition

• n. A pseudonym used by a writer. Also called nom de plume.

from Wiktionary, Creative Commons Attribution/Share-Alike License

• n. A fictitious name used by an author in place of their actual name.

from the GNU version of the Collaborative International Dictionary of English

• n. a name assumed by an author; a pseudonym or nom de plume.
• n. See under Name.

from The Century Dictionary and Cyclopedia

• n. A name assumed by an author for the ostensible purpose of concealing his identity; a nom de plume; a literary pseudonym.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• n. an author's pseudonym