Hard slant's adopted in assembly (7)
I believe the answer is:
chamber
'assembly' is the definition.
(chamber is a kind of assembly)
'hard slant's adopted' is the wordplay.
I cannot really see how this works, but
'hard' could be 'h' (abbreviation used in pencil classifications) and 'h' is located in the answer.
The remaining letters 'camber' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'in' acts as a link.
Can you help me to learn more?
(Other definitions for chamber that I've seen before include "Room - part of a legislature" , "Room where a judge transacts business" , "A formal room as for judge" , "Bedroom" , "Judicial assembly - room" .)