Give later instructions about deliveries on journey (8)
I believe the answer is:
override
'give later instructions' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'deliveries on journey' is the wordplay.
'deliveries' becomes 'over' (a cricket over consists of six deliveries).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'journey' becomes 'ride' (ride is a kind of journey).
'over'+'ride'='OVERRIDE'
'about' is the link.
Can you help me to learn more?
(Other definitions for override that I've seen before include "Cancel by higher authority" , "Annul" , "Take manual control" , "Use one's authority to reject or cancel a decision" , "Countermand" .)