Wise man never initially volunteers for battle (7)
I believe the answer is:
magenta
'for battle' is the definition.
(Magenta is an example)
'wise man never initially volunteers' is the wordplay.
'wise man' becomes 'mage' (I've seen this in other clues).
'initially' suggests taking the first letters.
'volunteers' becomes 'TA' (abbreviation for Territorial Army).
The first letter of 'never' is 'n'.
'mage'+'n'+'ta'='MAGENTA'
(Other definitions for magenta that I've seen before include "Name tag (anag) - colour" , "A crimson dye" , "Deep purplish red" , "this might be an ink" , "French victory" .)