Bravado John displayed to some extant in training area (4)
I believe the answer is:
dojo
'extant in training area' is the definition.
The definition suggests a singular noun which matches the answer.
'bravado john displayed to some' is the wordplay.
'to some' says the answer is hidden in the clue.
'DOJO' can be found hidden inside 'bravado john displayed'.
Can you help me to learn more?
(Other definitions for dojo that I've seen before include "Combat centre" , "place of karate" .)