Wound up mate originally in a cunning volte-face (6)
I believe the answer is:
trauma
'wound' is the definition.
(a trauma is an injury or wound)
'up mate originally in a cunning volte-face' is the wordplay.
'originally' suggests taking the first letters.
'in' indicates putting letters inside.
'cunning' becomes 'art' (both can mean artfulness or trickery).
'volte-face' says the letters should be written backwards (a volte-face is changing to the opposite direction).
The initial letters of 'up mate' is 'um'.
'a'+'art'='aart'
'aart' in reverse letter order is 'traa'.
'um' put within 'traa' is 'TRAUMA'.
(Other definitions for trauma that I've seen before include "Shock to the body or mind" , "Extreme shock" , "Nervous shock" , "Emotional damage" , "Shock with long-lasting effects" .)