The Collaborative International Dictionary of English v.0.48:

Sursum corda \Sur"sum cor"da\ [L. sursum upward + corda hearts.]
   (Eccl.)
   In the Eucharist, the versicles immediately before the
   preface, inviting the people to join in the service by
   "lifting up the heart" to God.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

sursum corda
    n 1: (Roman Catholic Church) a Latin versicle meaning `lift up
         your hearts'