'pre-communion' originates from Latin and Old French elements: the prefix 'pre-' (from Latin 'prae') meaning 'before', combined with 'communion' (from Latin 'communio').

'communion' passed into English via Old French 'comunion' from Latin 'communio' (from 'communis' meaning 'common'); the prefix 'pre-' (from Latin 'prae') was attached in English to indicate 'before', producing the compound 'pre-communion'.

Initially, 'communion' primarily meant 'sharing' or 'common participation'; over time it came to denote specifically the Christian rite of the Eucharist, and 'pre-communion' came to mean 'before that rite'.