That well-read old Rugby boy (3,5)
I believe the answer is:
tom brown
'that well-read old rugby' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'boy' is the wordplay.
I cannot quite see how this works, but
'boy' could be 'tom' and 'tom' is present in the answer.
The remaining letters 'brown' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for tom brown that I've seen is " schoolboy".)