Smoke one gets initially in vehicle (5)
I believe the answer is:
cigar
'smoke' is the definition.
(smoke can mean a cigar)
'one gets initially in vehicle' is the wordplay.
'one' becomes 'I' (Roman numeral).
'initially' indicates taking the first letters.
'in' means one lot of letters goes inside another.
'vehicle' becomes 'car' (car is a kind of vehicle).
The initial letter of 'gets' is 'g'.
'i'+'g'='ig'
'ig' put inside 'car' is 'CIGAR'.
(Other definitions for cigar that I've seen before include "Item for smoking" , "Close, but no ___ !" , "A real smoke!" , "Cylinder of tobacco" , "Havana, perhaps" .)