Money I had as cover (3)
I believe the answer is:
lid
'cover' is the definition.
(I know that lid is a type of cover)
'money i had' is the wordplay.
'money' becomes 'l' (L can mean 'pounds').
'i had' becomes 'I'd' (contraction).
'l'+'id'='LID'
'as' is the link.
(Other definitions for lid that I've seen before include "Cover for box or eye" , "Receptacle cover" , "Cover for box or pot" , "Cap or top for container" , "Bottle or jar top" .)