Good Tory, concealing black binder (4)
I believe the answer is:
glue
'binder' is the definition.
(I've seen this in another clue)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for glue that I've seen before include "agent with sticking power" , "Sticky substance" , "Sticky stuff" , "Stick together" , "Gum" .)