The Collaborative International Dictionary of English v.0.48:

Popish \Pop"ish\, a.
   Of or pertaining to the pope; taught or ordained by the pope;
   hence, of or pertaining to the Roman Catholic Church; --
   often used opprobriously. -- Pop"ish*ly, adv. --
   Pop"ish*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

popishly
    adv 1: like the Pope; in a popish manner