Virile Chinese leader once restricting church (5)
I believe the answer is:
macho
'virile' is the definition.
(I've seen this before)
'chinese leader once restricting church' is the wordplay.
'chinese leader once' becomes 'Mao' (Chairman Mao).
'restricting' is an insertion indicator.
'church' becomes 'ch' (common abbreviation).
'mao' enclosing 'ch' is 'MACHO'.
(Other definitions for macho that I've seen before include "Ostentatiously virile" , "Assertively masculine" , "Jock" , "Laddish" , "Aggressively male" .)