Novelist retaining hard copy (4)
I believe the answer is:
echo
'copy' is the definition.
(thesaurus)
'novelist retaining hard' is the wordplay.
'novelist' becomes 'eco' (Umberto Eco).
'retaining' means one lot of letters goes inside another.
'hard' becomes 'h'.
'eco' going around 'h' is 'ECHO'.
(Other definitions for echo that I've seen before include "from Brussels?" , "Languishing nymph" , "next to delta" , "Send back" , "Return of sound waves" .)