Hide point of heroin needle -- it can support one's habit (10)
I believe the answer is:
coathanger
'heroin needle it can support one's habit' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'hide point' is the wordplay.
'hide' becomes 'coat' (an animal's coat).
'point' becomes 'hanger' (I can't explain this - if you can you should believe this answer much more).
'coat'+'hanger'='COATHANGER'
'of' is the link.
Can you help me to learn more?
(Another definition for coathanger that I've seen is " Curved piece of wood with a hook in a wardrobe".)