Motor race, blooming thing (9)
I believe the answer is:
carnation
'blooming thing' is the definition.
(carnation is a kind of flower)
'motor race' is the wordplay.
'motor' becomes 'car' (informal term for car).
'race' becomes 'nation' (both can mean a national or ethnic group).
'car'+'nation'='CARNATION'
(Other definitions for carnation that I've seen before include "Flower like pink" , "Pink/white/red flower" , "Showy flower" , "Flower suitable for buttonhole ..." , "Pink - garden flower" .)