One is beaten resoundingly (and repeatedly?) (3-3)
I believe the answer is:
tam-tam
'one is beaten' is the definition.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for tam-tam that I've seen before include "Large metal gong" , "Large musical gong" , "Percussion instrument" , "Large orch. gong" .)