Alan resolved to maintain a bit of defiance - a court winner (5)
I believe the answer is:
nadal
'alan resolved to maintain a bit of defiance a court winner' is the definition.
I can't tell whether this definition defines the answer.
'alan resolved to maintain a bit of defiance' is the wordplay.
'resolved' indicates an anagram.
'to maintain' means one lot of letters goes inside another (maintain can mean to keep or preserve).
'a bit of' indicates taking the first letters.
The first letter of 'defiance' is 'd'.
'alan' anagrammed gives 'naal'.
'naal' enclosing 'd' is 'NADAL'.
Can you help me to learn more?
(Other definitions for nadal that I've seen before include "Top tennis player" , "Star with a 30 [RACKET]" , "Rafael __, Spanish tennis player" , "court figure" , "tennis champion" .)