hierarch
Concise Oxford English Dictionary © 2008 Oxford University Press:
hierarch /ˈhʌɪərɑːk/
▶noun a chief priest, archbishop, or other leader.
– origin ME: via med. L. from Gk hierarkhēs, from hieros ‘sacred’ + arkhēs ‘ruler’.
'hierarch' also found in these Oxford entries:

