'dean' originates from Late Latin, specifically the word 'decanus,' where the root from 'decem' meant 'ten' and the suffix '-anus' meant 'pertaining to' (hence 'leader of ten').

'decanus' transformed into Old French/Anglo-Norman 'deien'/'dean' and eventually became the modern English word 'dean'.

Initially, it meant 'leader of a group of ten (monks or soldiers),' later a church official overseeing a chapter, and in modern usage also 'head of a faculty or college division'.