Correspondent shot casualty in US (8)
I believe the answer is:
reporter
'correspondent' is the definition.
(thesaurus)
'shot casualty in us' is the wordplay.
'shot' becomes 'report' (report can mean a gunshot).
'casualty in us' becomes 'ER' (emergency room, US equivalent to casualty dept.).
'report'+'er'='REPORTER'
(Other definitions for reporter that I've seen before include "Hack" , "Newspaperman" , "One writing in newspaper" , "One gives us the news" , "Newspaper correspondent, journalist" .)