'excommunicate' originates from Medieval Latin, specifically the word 'excommunicare', where the prefix 'ex-' meant 'out of' and 'communicare' meant 'to share, to make common'.

'excommunicate' changed from Medieval Latin 'excommunicare' into Late Middle English (via ecclesiastical use) and eventually became the modern English word 'excommunicate'.

Initially, it meant 'to put out of communion (with the church)', and over time it has retained that primary meaning while also extending metaphorically to general social exclusion.