Unnamed (9)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
'unnamed' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for anonymous that I've seen before include "Incognito" , "Unidentified" , "Not identified by name" , "Of unknown identity" , "Having no known name" .)