Starter, possibly at Ascot? (6)
I believe the answer is:
course
'starter possibly' is the definition.
(I know that appetizer is a type of course)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for course that I've seen before include "Route or meal segment" , "Direction taken or intended, as in race" , "Route; studies" , "Layer (of bricks)" , "fish, possibly" .)