One in fifteen in Society voting in Great Britain approve (9)
I believe the answer is:
springbok
'one in fifteen' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'society voting in great britain approve' is the wordplay.
'society' becomes 's' (common abbreviation in names of organisations).
'voting' becomes 'pr' (I can't explain this - if you can you should give a lot more credence to this answer).
'great britain' becomes 'gb'.
'approve' becomes 'ok' (synonyms).
's'+'pr'+'in'+'gb'+'ok'='SPRINGBOK'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for springbok that I've seen before include "Antelope" , "antelopes" , "South African symbol" , "jumper" , "Sportsman" .)