Issue Fed on call raised (7)
I believe the answer is:
emanate
'issue' is the definition.
(both can mean to give out or radiate)
'fed on call raised' is the wordplay.
'fed' becomes 'ate' ('eat' can be a synonym of 'feed').
'on' means one lot of letters go next to another.
'call' becomes 'name' (as in calling or naming someone something).
'raised' shows that the letters should be reversed in order (going up in a down clue).
'name' reversed gives 'eman'.
'ate' put after 'eman' is 'EMANATE'.
(Other definitions for emanate that I've seen before include "Come forth" , "Flow or proceed from" , "Come out (of source)" , "Send out" , "Manatee (anag.)" .)