'ante-baptismal' originates from Latin and Late Latin/Greek elements: the Latin prefix 'ante-' meaning 'before' combined with 'baptismal', ultimately from Greek 'baptizein' (via Late Latin 'baptismus').

'baptismal' comes from Late Latin 'baptismus' < Greek 'baptisma' < 'baptizein' ('to dip, baptize'); the prefix 'ante-' (Latin 'ante', 'before') was attached in English to form the compound 'ante-baptismal'.

Initially it denoted something occurring before or in preparation for baptism; this basic sense has been retained in modern usage.