Debate when the throwing event is back on (10)
I believe the answer is:
discussion
'debate' is the definition.
(I've seen this before)
'the throwing event is back on' is the wordplay.
'the throwing event' becomes 'discus' (track and field event).
'back' shows that the letters should be reversed in order.
'is' reversed gives 'si'.
'discus'+'si'+'on'='DISCUSSION'
'when' acts as a link.
(Other definitions for discussion that I've seen before include "when hot air's emitted?" , "argument" , "Debate, conversation" .)