Motor competition not entirely uplifting (3)
I believe the answer is:
car
'motor' is the definition.
(I've seen this before)
'competition not entirely uplifting' is the wordplay.
'competition' becomes 'race' (race is a kind of competition).
'not entirely' means to remove the last letter.
'uplifting' shows that the letters should be reversed in order.
'race' with its last letter taken off is 'rac'.
'rac' in reverse letter order is 'CAR'.
(Other definitions for car that I've seen before include "4-wheeled vehicle" , "Passenger vehicle" , "saloon perhaps" , "Automobile" , "Private transport" .)