Horse, one of five in point-to-point? (6)
I believe the answer is:
equine
'horse' is the definition.
(thesaurus)
'one of five in point-to-point?' is the wordplay.
'one of five' becomes 'quin' (I've seen this before).
'in' indicates putting letters inside.
'point' becomes 'e' (E is an example).
'to point?' becomes 'e' (E is an example).
'e'+'e'='ee'
'quin' placed inside 'ee' is 'EQUINE'.
(Other definitions for equine that I've seen before include "Like horses" , "Horsey" , "Relating to a horse" , "Horse or donkey, perhaps" , "Horsy" .)