Race past vehicle, seeing red (9)
I believe the answer is:
carnation
'red' is the definition.
(thesaurus)
'race past vehicle' is the wordplay.
'race' becomes 'nation' (I've seen this before).
'past' means one lot of letters go next to another.
'vehicle' becomes 'car' (car is a kind of vehicle).
'nation' after 'car' is 'CARNATION'.
'seeing' acts as a link.
(Other definitions for carnation that I've seen before include "Showy flower" , "Flower suitable for buttonhole ..." , "Pink/white/red flower" , "Pink - garden flower" , "Not in a car (anag) - plant" .)