'apostolate' originates from Late Latin, specifically the word 'apostolatus', where 'apostolus' meant 'one sent' or 'messenger'.

'apostolate' changed from Late Latin 'apostolatus' (and via Medieval Latin/Old French forms such as 'apostolat') and eventually became the modern English word 'apostolate'.

Initially, it meant 'the office or term of an apostle,' but over time it has also come to mean 'the missionary work or evangelistic activity associated with apostles or apostolic figures'.