One spotted curtain length turned up, concealing nothing (7)
I believe the answer is:
leopard
'one spotted' is the definition.
(I know that leopard are usually patched)
'curtain length turned up concealing nothing' is the wordplay.
'curtain' becomes 'drape' (synonyms).
'length' becomes 'l' (abbreviation in geometry).
'turned up' says the letters should be written in reverse.
'concealing' indicates putting letters inside.
'nothing' becomes 'O' (looks like zero - 0).
'drape'+'l'='drapel'
'drapel' in reverse letter order is 'lepard'.
'lepard' going around 'o' is 'LEOPARD'.
(Other definitions for leopard that I've seen before include "Panther" , "Large spotted cat" , "Animal -- per load (anag)" , "Powerful cat" , "Spotted animal" .)