Source : Webster's Revised Unabridged Dictionary (1913)

Pax \Pax\, n.
   Friendship, or a friend; -- esp. in the phrases to make pax
   with, to make friends with, to be good pax, to be good
   friends; also, truce; -- used esp. interjectionally. [Eng.
   Schoolboy Slang]

Pax \Pax\, n. [L. pax peace. See {Peace}.]
   1. (Eccl.) The kiss of peace; also, the embrace in the
      sanctuary now substituted for it at High Mass in Roman
      Catholic churches.

   2. (R. C. Ch.) A tablet or board, on which is a
      representation of Christ, of the Virgin Mary, or of some
      saint and which, in the Mass, was kissed by the priest and
      then by the people, in medi[ae]val times; an osculatory.
      It is still used in communities, confraternities, etc.

            Kiss the pax, and be quiet like your neighbors.
                                                  --Chapman.

Source : WordNet®

pax
     n : (Roman Catholic Church) a greeting signifying Christian love
         for those assisting at the Eucharist [syn: {kiss of peace}]