Be more than relatively stupefied, unconscious at the start (9)
I believe the answer is:
outnumber
'be more than' is the definition.
(I've seen this before)
'relatively stupefied unconscious at the start' is the wordplay.
'relatively stupefied' becomes 'number' (ie more numb).
'unconscious' becomes 'out' ('out' can be similar in meaning to 'unconscious').
'at the start' says to put letters next to each other.
'number' after 'out' is 'OUTNUMBER'.
(Other definitions for outnumber that I've seen before include "Be more numerous than" , "Exceed in figures" , "Have more (eg troops) than" , "Be too many for in contest or conflict" , "Be in the majority" .)