Dish youngster eats sport being over (6)
I believe the answer is:
tureen
'dish' is the definition.
(tureen is a kind of dish)
'youngster eats sport being over' is the wordplay.
'youngster' becomes 'teen' (I've seen this before**).
'eats' is an insertion indicator.
'sport' becomes 'ru' (rugby union).
'being over' shows that the letters should be reversed in order.
'ru' in reverse letter order is 'ur'.
'teen' going around 'ur' is 'TUREEN'.
(Other definitions for tureen that I've seen before include "It holds soup" , "Soup vessel" , "Soup-dish" , "Deep bowl for serving soup" , "Soup container" .)