That of the crowd at the New Den? (4)
I believe the answer is:
roar
'den?' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for roar that I've seen before include "Deep loud sound as of lion or bull" , "Yell" , "Shout loudly" , "Cry (as a lion)" , "24 [BOOM]" .)