Lord Bradman, perhaps, second-to-none (6)
I believe the answer is:
adonai
'lord' is the definition.
(I've seen this before)
'bradman perhaps second-to-none' is the wordplay.
I cannot really see how this works, but
'bradman' could be 'don' and 'don' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for adonai that I've seen before include "Name for God (Hebrew)" , "Lord" , "in God's name" .)