Coach shortened odds saddling thoroughbred (9)
I believe the answer is:
charabanc
'coach' is the definition.
(type of coach or bus)
'shortened odds saddling thoroughbred' is the wordplay.
'shortened' means to remove the last letter.
'odds' becomes 'chance' (the chance of something happening).
'saddling' indicates putting letters inside (some letters cover up like a saddle).
'thoroughbred' becomes 'arab' (type of horse).
'chance' with its final letter taken away is 'chanc'.
'chanc' placed around 'arab' is 'CHARABANC'.
(Other definitions for charabanc that I've seen before include "E.g. transport" , "Old tourist coach" , "Early coach" , "Former coach" , "An ABC arch (anag) - early excursion bus" .)