Arrive without a ticket and go down after those attending (9)
I believe the answer is:
gatecrash
'arrive without a ticket' is the definition.
I can't tell whether this definition defines the answer.
'go down after those attending' is the wordplay.
'go down' becomes 'crash' (crashing is a kind of going down).
'after' says to put letters next to each other.
'those attending' becomes 'gate' (the number of people attending a sporting event).
'crash' after 'gate' is 'GATECRASH'.
'and' is the link.
Can you help me to learn more?
(Other definitions for gatecrash that I've seen before include "join party unofficially" , "join party if not wanted" , "to do so uninvited" , "Try to get in for free" , "enter without invitation" .)