Main event? (7)
I believe the answer is:
This clue could be a double definition.
'main' is the first definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'event?' is the second definition.
(regatta is a kind of event)
Can you help me to learn more?
(Other definitions for regatta that I've seen before include "Boating event" , "Series of boat races" , "Boat race-meeting" , "E.g. Henley" , "Sporting event with boat or yacht races" .)