source: By Darth malus at English Wikipedia - Transferred from en.wikipedia to Commons., Public Domain

1. the sharing or exchanging of intimate thoughts and feelings, especially when the exchange is on a mental or spiritual level:

｟かたく｠ «…との» 思想［感情］の交換; 親交; 霊的交渉 «with»

e.g. in this churchyard communion with the dead was almost palpable.

common participation in a mental or emotional experience:

e.g. popular festivals where all take part in joyous communion.

2. (often Communion or Holy Communion) the service of Christian worship at which bread and wine are consecrated and shared. See Eucharist.

〖C-〗聖餐（せいさん）式, 聖体拝領(→ Holy Communion)

the consecrated bread and wine so administered and received:

e.g. the priests gave him Holy Communion.

3. a relationship of recognition and acceptance between Christian churches or denominations, or between individual Christians or Christian communities and a church (signified by a willingness to give or receive the Eucharist):

〖集合的に; 単複両扱い〗信仰を共にする人たち, 同一教会員; 宗派

e.g. the Eastern Churches are not in communion with Rome.

a group of Christian communities or Churches which recognize one another's ministries or that of a central authority. See also Anglican Communion.

receive bread and wine that has been consecrated at a Eucharist, as a sacramental, spiritual, or symbolic act of receiving the presence of Christ.

late Middle English: from Latin communio(n-), from communis (see common).