a·non·y·mous / əˈnänəməs/ • adj. (of a person) not identified by name; of unknown name: the anonymous author of Beowulf. ∎  having no outstanding, individual, or unusual features; unremarkable or impersonal: the anonymous black car waiting to take him to the airport. ∎  used in names of support groups for addicts of a substance or behavior to indicate the confidentiality maintained among members of the group: Alcoholics Anonymous Debtors Anonymous.DERIVATIVES: an·o·nym·i·ty / ˌanəˈnimitē/ n.a·non·y·mous·ly adv.

anonymous XVII. f. late L anōnymus — Gr. anṓnumos, f. AN-2 + ónoma NAME.
Hence anonymity XIX.