Enrage VIP slammed in news source (9)
I believe the answer is:
grapevine
'news source' is the definition.
(I've seen this before)
'enrage vip slammed' is the wordplay.
'slammed' indicates an anagram.
'enrage'+'vip'='enragevip'
'enragevip' is an anagram of 'GRAPEVINE'.
'in' acts as a link.
(Other definitions for grapevine that I've seen before include "whose constituents go to press" , "(Informal) means of spreading information?" , "where fruit is grown" , "News source" , "Bush telegraph" .)