Unsophisticated fictional detective picked up play on words (8)
I believe the answer is:
homespun
'unsophisticated' is the definition.
(I've seen this before)
'fictional detective picked up play on words' is the wordplay.
'fictional detective' becomes 'Holmes' (Sherlock Holmes).
'picked up' indicates a 'sounds like' (homophone) clue.
'play on words' becomes 'pun' (synonyms).
'holmes' is a homophone of 'homes'.
'homes'+'pun'='HOMESPUN'
(Other definitions for homespun that I've seen before include "Unsophisticated -- posh menu (anag)" , "Folksy - open mush (anag)" , "Unsophisticated; a coarse fabric" , "Rustic" , "Unsophisticated - not made in mill" .)