Country sport - two codes, including amateur (5)
I believe the answer is:
rural
'country' is the definition.
(I know that country can be written as rural)
'sport two codes including amateur' is the wordplay.
'sport' becomes 'RU' (rugby union).
'two codes' becomes 'rl' (I can't justify this - if you can you should give a lot more credence to this answer).
'including' indicates putting letters inside.
'amateur' becomes 'a'.
'rl' placed around 'a' is 'ral'.
'ru'+'ral'='RURAL'
Can you help me to learn more?
(Other definitions for rural that I've seen before include "Relating to country life" , "Sort of dean" , "Countrylike" , "Characteristic of country life" , "Arcadian" .)