Big game reserve visited by a Member of Parliament? (5,4)
I believe the answer is:
super bowl
'big game' is the definition.
(I've seen this before)
'reserve visited by a member of parliament?' is the wordplay.
'reserve' becomes 'sub' (I've seen this in another clue).
'visited by' indicates putting letters inside.
'a' becomes 'per' (eg 'one a day' means 'one per day').
'member of parliament?' becomes 'owl' ('parliament' is the collective noun for 'owl').
'sub' placed around 'per' is 'superb'.
'superb'+'owl'='SUPER BOWL'
(Other definitions for super bowl that I've seen before include "big game in US" , "Championship game of the US NFL" , "Big event in American football" , "annual championship game" , "NFL championship match" .)