a·non·y·mous 
(ə-nŏnə-məs)
(ə-nŏnə-məs)adj.
1. Having an unknown or unacknowledged name: an anonymous author.
2. Having an unknown or withheld authorship or agency: an anonymous letter.
3. Having no distinctive character or recognition factor: "They were carried over a bridge above an anonymous parade of shops" (Elizabeth Speller).
[From Late Latin anōnymus, from Greek anōnumos, nameless : an-, without; see A-1 + onuma, name (influenced by earlier nōnumnos, nameless); see n-men- in the Appendix of Indo-European roots.]
a·nony·mous·ly adv.
a·nony·mous·ness n.