Understanding the crowd (9)
I believe the answer is:
gathering
I believe this is a double definition.
'understanding' is the first definition.
('gather' can be a synonym of 'understand')
'crowd' is the second definition.
(a crowd of people)
'the' acts as a link.
(Other definitions for gathering that I've seen before include "party" , "bee" , "Assembly, meeting" , "Harvesting" , "convention?" .)