Denied row involved quilt (9)
I believe the answer is:
eiderdown
'quilt' is the definition.
(eiderdown is a kind of quilt)
'denied row involved' is the wordplay.
'involved' is an anagram indicator (involved can mean confusing or complex).
'denied'+'row'='deniedrow'
'deniedrow' anagrammed gives 'EIDERDOWN'.
(Other definitions for eiderdown that I've seen before include "Find cover" , "I wondered about this warm bed covering" , "Soft quilt filled with duck feathers" , "What might keep one warm" , "Warm bed cover" .)