Starter, perhaps, or where you might find one (6)
I believe the answer is:
course
'starter perhaps' is the definition.
(I know that appetizer is a type of course)
'or where you might find one' is the wordplay.
I cannot really see how this works, but
'you' could be 'u' (commonly used in online communication) and 'u' is found within the answer.
'or' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for course that I've seen before include "Route of the race" , "Route; lectures" , "Mode, of action say" , "Route or meal segment" , "Part of a meal or a series of lessons" .)