Writer around about a nut (5)
I believe the answer is:
pecan
'a nut' is the definition.
(pecan is a kind of nut)
'writer around about' is the wordplay.
'writer' becomes 'pen' (I've seen this before).
'around' means one lot of letters goes inside another.
'about' becomes 'ca' (abbreviation for 'circa').
'pen' placed around 'ca' is 'PECAN'.
(Other definitions for pecan that I've seen before include "Nutty type" , "Nut of American hickory tree" , "Oval nut of south central United States" , "Edible nut like a smooth walnut" , "of nuts" .)