intercommunion

Communion, relationship, or association between persons or groups.

The practice by which members of different Christian denominations can receive Communion at one another’s Eucharistic services or at a common service.

Communion one with another; intimate intercourse.

Mutual communion.

communion (association) between people or groups

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

participation in Holy Communion by members of more than one church (eg Catholic and Orthodox)