'anonymous' definitions:

Definition of 'anonymous'

(from WordNet)
adjective
Having no known name or identity or known source; "anonymous authors"; "anonymous donors"; "an anonymous gift" [syn: anonymous, anon.] [ant: onymous]
adjective
Not known or lacking marked individuality; "brown anonymous houses"; "anonymous bureaucrats in the Civil Service"

Synonyms of 'anonymous'

From: Moby Thesaurus