Set aside the decision about the trip (8)
I believe the answer is:
'set aside' is the definition.
'about the trip' is the wordplay.
'about' becomes 'over' (both can mean around).
'the trip' becomes 'ride' (eg a trip in a car).
'the decision' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for override that I've seen before include "Counteract the normal operation" , "Set aside by superior authority" , "Take manual control" , "Use one's authority to reject or cancel a decision" , "Supersede" .)