The Collaborative International Dictionary of English v.0.48:

Romish \Rom"ish\, a.
   Belonging or relating to Rome, or to the Roman Catholic
   Church; -- frequently used in a disparaging sense; as, the
   Romish church; the Romish religion, ritual, or ceremonies.
   [1913 Webster]

WordNet (r) 3.0 (2006):

romish
    adj 1: of or relating to or supporting Romanism; "the Roman
           Catholic Church" [syn: Roman, R.C., Romanist,
           romish, Roman Catholic, popish, papist,
           papistic, papistical]