Crowd noises (5)
I believe the answer is:
roars
'crowd noises' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for roars that I've seen before include "Sounds like a lion" , "Deep bellows" , "Bellows, hollers" , "Bellows like a bull" , "'Deep, bellowing bursts of sound (5)'" .)