Way in which ginger's used? (7)
(Other definitions for cat flap that I've seen before include "One admitting queen" , "Entry for pet" , "Opening in door for pet" , "cutting through doorway" .)
'way in' is the definition.
(entrance or way in for a cat)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Another definition for catflap that I've seen is " small entrance".)