Bill in close-fitting jacket for performance (6,3)
I believe the answer is:
double act
'performance' is the definition.
(I've seen this before)
'bill in close-fitting jacket' is the wordplay.
'bill' becomes 'ac'.
'in' is an insertion indicator.
'close-fitting jacket' becomes 'doublet' (doublet is a kind of jacket. I am not sure about the 'close-fitting' bit.**).
'ac' placed into 'doublet' is 'DOUBLE ACT'.
'for' is the link.
Can you help me to learn more?
(Other definitions for double act that I've seen before include "What has four legs and makes us laugh" , "Funny man and stooge, perhaps" , "Comic pair" , "What was Hardy into" , "Partnership" .)