Inside-out cover on fish basket (5)
I believe the answer is:
creel
'basket' is the definition.
(basket for holding fish)
'inside-out cover on fish' is the wordplay.
'inside out' means to remove the middle letters (throwing the inside away).
'on' means one lot of letters go next to another.
'fish' becomes 'eel' (eel is a kind of fish).
'cover' with its middle taken out is 'cr'.
'cr'+'eel'='CREEL'
(Other definitions for creel that I've seen before include "Lobster catcher" , "lobster basket" , "Lobster trap" , "Fish-basket" , "Bobbin rack" .)