Writer offering brill Old English (5)
I believe the answer is:
defoe
'writer' is the definition.
(Daniel Defoe)
'brill old english' is the wordplay.
'brill' becomes 'def' (both are slang terms meaning excellent).
'old english' becomes 'oe'.
'def'+'oe'='DEFOE'
'offering' acts as a link.
(Other definitions for defoe that I've seen before include "Author of Robinson Crusoe, d. 1731" , "pamphleteer and novelist" , "Daniel ---, wrote Moll Flanders" , "Robinson Crusoe's creator, d. 1731" , "Writer of Moll Flanders" .)