Inland Revenue taking on golf club (4)
I believe the answer is:
iron
'golf club' is the definition.
(I've seen this before)
'inland revenue taking on' is the wordplay.
'inland revenue' becomes 'ir'.
'taking' means one lot of letters go next to another.
'ir'+'on'='IRON'
(Other definitions for iron that I've seen before include "Very robust" , "Wellington was known as the .... Duke" , "Smooth things" , "A magnet attracts it" , "Press - element" .)