Some fearless nobleman (4)
I believe the answer is:
earl
'nobleman' is the definition.
(member of the nobility)
'some fearless' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'EARL' is hidden in the letters of 'fearless'.
(Other definitions for earl that I've seen before include "Male equivalent of a countess" , "Rank below marquess" , "Jimmy Carter's middle name" , "... Grey, fragrant Oriental tea" , "Real (anag) - nobleman" .)