Old pitch support overturned game (7)
I believe the answer is:
diabolo
'game' is the definition.
(I've seen this before)
'old pitch support overturned' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'pitch' becomes 'lob' (both can mean to throw).
'support' becomes 'aid' (to aid is to help or support).
'overturned' shows that the letters should be reversed in order.
'o'+'lob'+'aid'='olobaid'
'olobaid' written backwards gives 'DIABOLO'.
(Other definitions for diabolo that I've seen before include "Top-on-a-string game" , "Game involving two sticks joined by a string and a spool-shaped object" , "Game involving sticks and spinning top" , "juggling performance?" , "Old game" .)