An outing in the fall (4)
I believe the answer is:
trip
I believe this clue is a double definition.
'an outing' is the first definition.
(I've seen this before)
'the fall' is the second definition.
(I've seen this before)
'in' is the link.
(Other definitions for trip that I've seen before include "a result of drug-taking" , "Journey - miss one's footing" , "Journey; make a mistake" , "Hallucinatory experience" , "Ride" .)