Article about the most prolific author? (4)
I believe the answer is:
anon
'the most prolific author?' is the definition.
(many anonymous works have been credited to 'anon')
'article about' is the wordplay.
'article' becomes 'an' (indefinite article).
'about' becomes 'on' (as in a book 'on' a certain topic).
'an'+'on'='ANON'
(Other definitions for anon that I've seen before include "Soon - nobody knows me" , "Having no known name" , "Soon; unnamed" , "Incognito (abbrev)" , "At another time, of old" .)