Cover, cap (3)

I believe the answer is:
lid
I believe this is a double definition.
'cover' is the first definition.
(lid is a kind of cover)
'cap' is the second definition.
(eg the lid of a bottle)
(Other definitions for lid that I've seen before include "Pie crust; cover" , "Cover for box or pot" , "Bottle or jar top" , "Kind of cover, may be hinged" , "Top or cover" .)