The last imaginable feline or horse (8)
I believe the answer is:
stallion
'horse' is the definition.
(I've seen this before)
'the last imaginable feline' is the wordplay.
I cannot really understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
'feline' could be 'lion' (lion is a kind of feline) and 'lion' is present in the answer.
The remaining letters 'sal' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'or' is the link.
Can you help me to learn more?
(Other definitions for stallion that I've seen before include "Mount" , "Male horse, often used for breeding" , "Male steed" , "Uncastrated adult male horse" , "Stud" .)