Japanese martial art using split bamboo swords (5)
I believe the answer is:
kendo
'japanese martial art using split bamboo swords' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for kendo that I've seen before include "Japanese fencing with bamboo staves" , "Japanese form of fencing" , "Japanese fighting" , "Fighting in Japan" , "Jap. fencing with staves" .)