Vehicle on route at last to give hoot (4)
I believe the answer is:
care
'give hoot' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'vehicle on route at last' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'on' says to put letters next to each other.
'at last' indicates one should take the final letters.
The final letter of 'route' is 'e'.
'car'+'e'='CARE'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for care that I've seen before include "Caution; keeping" , "Have concern or regard" , "Serious attention and thought" , "The provision of what's necessary, for health say" , "See 16" .)