To score as a writer (6)
I believe the answer is:
scribe
I believe this is a double definition.
'to score' is the first definition.
(scribing is a kind of scoring)
'a writer' is the second definition.
(scribe is a kind of writer)
'as' acts as a link.
(Other definitions for scribe that I've seen before include "Ancient copyist of manuscripts" , "Document copier (hist.)" , "Scholar of Jewish law" , "Letter-writer of old" , "One copied documents before the invention of printing" .)