Two, naked, wrestling old martial art (3,4,2)
I believe the answer is:
tae kwon do
'martial art' is the definition.
(tae kwon do is a kind of martial art)
'two naked wrestling old' is the wordplay.
'wrestling' indicates an anagram.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'two'+'naked'='twonaked'
'twonaked' is an anagram of 'taekwond'.
'taekwond'+'o'='TAE KWON DO'
(Other definitions for tae kwon do that I've seen before include "Koreans fighting" , "Martial activity" , "Martial art Olympic event since 2000" , "Martial art display" , "Modern Korean martial art" .)