Eject assembled crowd (7)
I believe the answer is:
turnout
'crowd' is the definition.
(I've seen this before)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for turnout that I've seen before include "The number of people who came to a function" , "those who showed up for meeting" , "Evict" , "number of people coming to meeting" , "Attendance figure" .)