Raise (a topic) for discussion (6)
I believe the answer is:
broach
'raise a topic for discussion' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for broach that I've seen before include "Start to talk about" , "Raise a topic for discussion" , "Open (container, subject)" , "Bring up a topic" , "Bring up or mention a subject" .)