Help Alice, say, at opening of event (9)
I believe the answer is:
cooperate
'help' is the definition.
(thesaurus)
'alice say at opening of event' is the wordplay.
'alice say' becomes 'cooper' (Alice Cooper).
'opening of' says to take the initial letters.
The first letter of 'event' is 'e'.
'cooper'+'at'+'e'='COOPERATE'
(Other definitions for cooperate that I've seen before include "work hand in glove" , "Help" , "Work together on a common enterprise" , "band together" , "Work constructively with others" .)