Wrath perhaps after tax put up in sport (6)
I believe the answer is:
tennis
'sport' is the definition.
(I've seen this before)
'wrath perhaps after tax put up' is the wordplay.
'wrath perhaps' becomes 'sin' (wrath is a kind of sin).
'after tax' becomes 'net' (I've seen this before).
'put up' is a reversal indicator.
'sin'+'net'='sinnet'
'sinnet' reversed gives 'TENNIS'.
'in' acts as a link.
(Other definitions for tennis that I've seen before include "Pete Sampras's game" , "Wimbledon game" , "Real or lawn game" , "Sent in, oddly, to play a sport" , "Racket-and-ball game" .)