At the time in question, the point (4)
I believe the answer is:
then
'at the time' is the definition.
(synonyms)
'the point' is the wordplay.
'point' becomes 'n' (N is an example).
'the'+'n'='THEN'
'in question' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for then that I've seen before include "Once upon a time" , "Consequently" , "At that time; next" , "Afterwards - as a result" , "soon?" .)