Spiritual Meaning:
Technically, to be excommunicated is to be denied access to the sacraments, so in dreams signifies being prevented from communicating with the Divine

Psychological / Emotional Perspective:
Emotionally, to find ourselves excommunicated in dreams suggests being cut off from a source of comfort.

Everyday Material Aspects:
As humans we have a strong need at times to belong to groups. When we dream of being excommunicated we must cope with feelings of rejection, and perhaps of disapproval.