Jumper's odds double (8)
I believe the answer is:
springer
'jumper's' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'odds double' is the wordplay.
'odds' becomes 'sp' (betting abbreviation for starting price).
'double' becomes 'ringer' (I've seen this before).
'sp'+'ringer'='SPRINGER'
Can you help me to learn more?
(Other definitions for springer that I've seen before include "Game dog" , "A bounder" , "Kind of spaniel" , "A spaniel; stone in arch" , "hound" .)