In the distance, one gets it by the kilo (5)
I believe the answer is:
metre
'kilo' is the definition.
The definition and answer can be both quantities as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'in the distance one gets it by' is the wordplay.
'in the distance' becomes 're' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'one' becomes 'me' (a setter might use 'one' to humourously mean 'me').
'gets' means one lot of letters go next to another.
'it' becomes ''t' (abbreviation. e.g. in 'tis).
'by' means one lot of letters go next to another.
'me' next to 't' is 'met'.
're' put after 'met' is 'METRE'.
'the' acts as a link.
Can you help me to learn more?
(Other definitions for metre that I've seen before include "Distance" , "Poetic rhythm" , "100cm" , "Alignment of feet determines such" , "Characteristic of feet" .)