The fellow at the back of the crowd is a reporter (8)
I believe the answer is:
pressman
'reporter' is the definition.
(thesaurus)
'the fellow at the back of the crowd' is the wordplay.
'the fellow' becomes 'man' (fellow can mean a man).
'at the back of' says to put letters next to each other.
'the crowd' becomes 'press' (to press can mean to crowd around).
'man' put after 'press' is 'PRESSMAN'.
'is a' acts as a link.
(Other definitions for pressman that I've seen before include "correspondent?" , "Male journalist" .)