WordNet (r) 3.0 (2006):

novena
    n 1: a Roman Catholic devotion consisting of prayers on nine
         consecutive days

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "novena":
   Mass, Nina from Carolina, bedtime prayer, camp meeting, church,
   church service, compline, devotions, divine service, duty, ennead,
   enneastyle, evening devotions, evensong, exercises, lauds, liturgy,
   matins, meeting, morning devotions, night song, nine, nonage,
   nonagon, none, nones, nonuplet, office, praise meeting, prayer,
   prayer meeting, prayers, prime, prime song, public worship,
   revival, revival meeting, service, sext, tent meeting, tierce,
   undersong, vesper, vespers, vigils, watch meeting, watch night,
   watch-night service