1) Alias 2) Pseudonym 1) An assumed or false name 2) Assumed name 3) Fictitious name 4) French word used in English 5) John Doe, commonly 6) Name 7) Nom de guerre 8) Pseudonym 9) Unidentified person 
person whose name is not given; pseudonym
• (n.) A notion which has no name, or which can not be expressed by a single English word. • (n.) One who is anonymous; also sometimes used for `pseudonym.`
An'o·nym noun [ French anonyme . See Anonymous .] 1. One who is anonymous; also sometimes used for 'pseudonym.' 2. A notion which has no name, or which can not be expressed by a single English word. [ R.] J. R. Seeley. 
anonym 1. With no name known or acknowledged. 2. Given, written, etc. by a person whose name is withheld. 3. A name used by someone to hide his or her identity. 4. Not easily distinguished from others or from one another because of a lack of individual features or character.
an assumed or false name. · an anonymous person or publication.