Curious when taken aback by excellent Japanese warrior (7)
I believe the answer is:
samurai
'japanese warrior' is the definition.
(I've seen this before)
'curious when taken aback by excellent' is the wordplay.
'curious' becomes 'rum' ('rum' can be a synonym of 'curious').
'when' becomes 'as'.
'taken aback' says the letters should be written backwards.
'by' means one lot of letters go next to another.
'excellent' becomes 'ai'.
'rum'+'as'='rumas'
'rumas' written backwards gives 'samur'.
'samur'+'ai'='SAMURAI'
(Other definitions for samurai that I've seen before include "Traditional Japanese warrior" , "military man" , "Feudal Japanese warrior" , "Former Japanese military caste member" , "Japanese fighter" .)