Be back in time for discussion (6)
I believe the answer is:
debate
'discussion' is the definition.
(debate is a kind of discussion)
'be back in time' is the wordplay.
'back' says the letters should be written backwards.
'in' means one lot of letters goes inside another.
'time' becomes 'date' (a date is a period of time).
'be' written backwards gives 'eb'.
'eb' going into 'date' is 'DEBATE'.
'for' is the link.
(Other definitions for debate that I've seen before include "Exchange of views" , "Verbal disputation" , "Argue the toss" , "Public discussion, perhaps a contest" , "Discuss through argument" .)