Doctor is averse initially to making bold claims (9)
I believe the answer is:
assertive
'making bold claims' is the definition.
I can't judge whether this defines the answer.
'doctor is averse initially to' is the wordplay.
'doctor' is an anagram indicator.
'initially' indicates taking the first letters.
The initial letter of 'to' is 't'.
'is'+'averse'+'t'='isaverset'
'isaverset' anagrammed gives 'ASSERTIVE'.
Can you help me to learn more?
(Other definitions for assertive that I've seen before include "Positive and outspoken" , "Forceful, dogmatic" , "Confident, self-assured" , "Confident in promoting one's own views" , "Confident or pushy" .)