Gong finally sounded interrupting dinner? (5)
I believe the answer is:
medal
'gong' is the definition.
(gong can mean a prize or medal)
'finally sounded interrupting dinner?' is the wordplay.
'finally' indicates one should take the final letters.
'interrupting' is an insertion indicator.
'dinner?' becomes 'meal' (dinner is a kind of meal).
The last letter of 'sounded' is 'd'.
'd' going inside 'meal' is 'MEDAL'.
(Other definitions for medal that I've seen before include "silver?" , "Prize; sounds like interfere" , "Prize disc for as for Olympic Games win" , "Religious or commenorative metal piece" , "An award, in slang a gong" .)