Popular present previously (2,7)
I believe the answer is:
in advance
'previously' is the definition.
Both the answer and definition are adverbs. Perhaps you can see a link between them that I can't see?
'popular present' is the wordplay.
'popular' becomes 'in'.
'present' becomes 'advance' (I can't explain this - if you can you should believe this answer much more).
'in'+'advance'='IN ADVANCE'
Can you help me to learn more?
(Other definitions for in advance that I've seen before include "Before the event" , "Ahead in place or time" , "early" , "Beforehand - can invade accordingly (2.7)" .)