Start court proceedings (5)
I believe the answer is:
serve
'start court proceedings?' is the definition.
(a serve can start a tennis match on a court)
This is the entire clue.
(Other definitions for serve that I've seen before include "Bring food to table" , "Perform duties for" , "Put the ball in play in 7 down" , "Function (as)" , "Work for; tennis stroke" .)