Huge noisy crowds or multitudes (6)
I believe the answer is:
hordes
I believe this clue is a double definition.
'huge noisy crowds' is the first definition.
(I've seen this before)
'multitudes' is the second definition.
(I know this)
(Other definitions for hordes that I've seen before include ".Shored up with crowds" , "Bands" , "Horsed around with the multitudes" , "Large moving crowds" , "Vast multitudes" .)