Jaunt producing endless rubbish (4)
I believe the answer is:
trip
'jaunt' is the definition.
('trip' can be a synonym of 'jaunt')
'endless rubbish' is the wordplay.
'endless' means to remove the last letter.
'rubbish' becomes 'tripe' ('tripe' can be a synonym of 'rubbish').
'tripe' with its final letter taken off is 'TRIP'.
'producing' acts as a link.
(Other definitions for trip that I've seen before include "Journey, excursion" , "Set off for" , "often occurring just before the fall" , "Catch one's foot" , "Hallucinogenic drug experience - lose one's balance" .)