Football code gets past a gem (4)
I believe the answer is:
ruby
'gem' is the definition.
(I know that ruby is a type of gem)
'football code gets past a' is the wordplay.
I cannot really see how this works, but
'football' could be 'ru' (rugby union - type of rugby football) and 'ru' is located in the answer.
'past' could be 'by' (as in years gone by) and 'by' is found within the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for ruby that I've seen before include "Fortieth anniversary stone" , "Vivid red" , "Deep 6 across" , "Gemstone - shade of red" , "Red precious stone" .)