Sparing prisoner returning after loud game (6)
I believe the answer is:
frugal
'sparing' is the definition.
('frugal' can be a synonym of 'sparing')
'prisoner returning after loud game' is the wordplay.
'prisoner' becomes 'lag' (I've seen this before).
'returning' says the letters should be written in reverse.
'after' means one lot of letters go next to another.
'loud' becomes 'f' (A musical term).
'game' becomes 'ru' (rugby union).
'lag' written backwards gives 'gal'.
'f'+'ru'='fru'
'gal' put after 'fru' is 'FRUGAL'.
(Other definitions for frugal that I've seen before include "Thrifty - meagre" , "Sparing, meagre" , "Practising economy" , "Thrifty or parsimonious" , "Abstemious" .)