Send in advance (7)
I believe the answer is:
forward
This clue is a double definition.
'send' is the first definition.
(forwarding is a kind of sending)
'in advance' is the second definition.
(thesaurus)
(Other definitions for forward that I've seen before include "going on" , "To the front" , "left-winger, maybe" , "Bold, overfamiliar" , "Ahead; impertinent" .)