Stumble across very short leaving party (5)
I believe the answer is:
disco
'party' is the definition.
(I've seen this in other clues)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for disco that I've seen before include "Club or party with dancing" , "Demonic spirit" , "Party with records" , "Musical party" , "party for dancers" .)