Fighting in Barking and Kew too (3,4,2)
I believe the answer is:
tae kwon do
'fighting' is the definition.
(I've seen this before)
'barking and kew too' is the wordplay.
'barking' indicates an anagram (UK slang for mad).
'and'+'kew'+'too'='andkewtoo'
'andkewtoo' is an anagram of 'TAE KWON DO'.
'in' acts as a link.
(Other definitions for tae kwon do that I've seen before include "Martial art Olympic event since 2000" , "Martial art display" , "Koreans fighting" , "Modern Korean martial art" , "sport" .)