'acacian' originates from the name 'Acacius', a bishop of Caesarea, where 'Acacius' was a prominent figure in early Christian theological debates.

'Acacius' transformed into the term 'Acacian' to describe followers of his teachings.

Initially, it referred specifically to followers of Acacius, but over time it has been used more broadly to describe any adherent of his philosophical school.