After that, the first of November (4)
I believe the answer is:
then
'after that' is the definition.
('then' can be a synonym of 'after that')
'the first of november' is the wordplay.
'first of' suggests taking the first letters.
The first letter of 'november' is 'n'.
'the'+'n'='THEN'
(Other definitions for then that I've seen before include "Subsequently - previously" , "soon?" , "Consequently" , "At that time; next" , "Afterwards - as a result" .)