.... and a great distance to find this one (5)
I believe the answer is:
miles
'and a great' is the definition.
I can't judge whether this definition defines the answer.
'distance to find this one' is the wordplay.
'distance' becomes 'mile' (mile is a unit of distance).
'to find this one' becomes 's' (I can't explain this - if you can you should give a lot more credence to this answer).
'mile'+'s'='MILES'
Can you help me to learn more?
(Other definitions for miles that I've seen before include "Distance units" , "'But I have promises to keep, and . . . . . to go before I sleep' (Frost)" , "Imperial units of length" , "a long way" .)