Relating to the right replacement for phys. ed. training (10)
I believe the answer is:
pertaining
'relating' is the definition.
('pertain' can be a synonym of 'relate')
'the right replacement for phys ed training' is the wordplay.
I cannot quite understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
'right' could be 'rain' (I have seen 'The right' mean 'rain' so perhaps 'right' could also mean 'rain') and 'rain' is present in the leftover letters.
'training' could be 'pe' (Physical Education) and 'pe' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'to' acts as a link.
Can you help me to learn more?