Spymaster in passage makes broadcast (8)
I believe the answer is:
transmit
'broadcast' is the definition.
(I know that broadcast can be written as transmit)
'spymaster in passage' is the wordplay.
'spymaster' becomes 'M' (M is the head of MIi in James Bond).
'in' is an insertion indicator.
'passage' becomes 'transit' (synonyms).
'm' inserted into 'transit' is 'TRANSMIT'.
'makes' acts as a link.
(Other definitions for transmit that I've seen before include "Send (a radio message)" , "Broadcast (a signal)" , "Send - communicate" , "Disseminate" , "F. name; Hamlet (anag.)" .)