Throwback not guaranteed to join monk’s do (7)
I believe the answer is:
tonsure
'do' is the definition.
(I know that tonsure is a do)
'throwback not guaranteed to join monk's' is the wordplay.
I cannot really see how this works, but
an anagram of 'not' is 'ton' which is located in the answer.
'guaranteed' could be 'sure' (I've seen this in other clues) and 'sure' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for tonsure that I've seen before include "Close-shaved hairstyle" , "bare patch" , "Monk's haircut" , "Bald bit" , "Monk's hair style" .)