Stick one's oar in as gong is heard (6)
I believe the answer is:
meddle
'stick one's oar in' is the definition.
(I've seen this before)
'gong is heard' is the wordplay.
'gong' becomes 'medal' (gong can mean a prize or medal).
'is heard' indicates a 'sounds like' (homophone) clue.
'medal' sounds like 'MEDDLE'.
'as' acts as a link.
(Other definitions for meddle that I've seen before include "Interfere in the affairs of others" , "Intrude in other people's affairs" , "Intrude, interfere" , "Mess with" , "Interfere or tamper" .)