Nobleman mostly primitive (4)
I believe the answer is:
earl
'nobleman' is the definition.
(earl is a kind of nobleman)
'mostly primitive' is the wordplay.
'mostly' means to remove the last letter.
'primitive' becomes 'early' (similar in meaning).
'early' with its last letter taken away is 'EARL'.
(Other definitions for earl that I've seen before include "... Grey, fragrant Oriental tea" , "Real (anag) - nobleman" , "Titled man" , "Peer (Br.)" , "Rank immediately above viscount" .)