'celebrant' originates from Latin, specifically the word 'celebrans', where the verb 'celebrare' meant 'to celebrate' and the adjective/root 'celeber' meant 'frequented, renowned'.

'celebrant' changed from Medieval/ Ecclesiastical Latin 'celebrans' (the present participle of 'celebrare') and entered English via ecclesiastical usage, eventually becoming the modern English noun 'celebrant'.

Initially, it meant 'one who celebrates or performs a celebration/ceremony', and over time it retained that primary sense while also extending to mean 'a participant in a celebration' (a reveler).