intercommunion

/IH0 N T ER0 K AH0 M Y UW1 N Y AH0 N/
noun
  1. 1

    Communion (association) between people or groups

  2. 2

    The participation, together, in Holy Communion of people from different denominations

  3. 3

    In Roman Catholicism, the theological principle which governs whether it is permissible for a Roman Catholic to partake of the Eucharist in a non-Catholic service, and vice versa

Source: https://en.wiktionary.org/wiki/intercommunion