Go over main points again as horse is backed? (5)
I believe the answer is:
recap
'go over main points again' is the definition.
(I've seen this before)
'horse is backed?' is the wordplay.
'horse' becomes 'pacer' (a horse which paces).
'is backed?' shows that the letters should be reversed in order.
'pacer' backwards is 'RECAP'.
'as' acts as a link.
(Other definitions for recap that I've seen before include "Quickly run through" , "Repeat of main points" , "Summarise briefly (abbr)" , "Summarise, run over" , "Summarising statement" .)