Now and subsequently - or in future (9)
I believe the answer is:
hereafter
'in future' is the definition.
(I've seen this before)
'now and subsequently' is the wordplay.
'now' becomes 'here' (I've seen this before).
'and' says to put letters next to each other.
'subsequently' becomes 'after' (I've seen this before).
'here'+'after'='HEREAFTER'
'or' is the link.
(Other definitions for hereafter that I've seen before include "Life in the future" , "Hence" , "In subsequent parts of legal document" .)