decanus

Decanus comes from Latin decem (ten). A decanus was the leader of a group of ten soldiers in the Roman army, or the leader of ten monks in a monastery. The word is a number: the boss of ten. In early Christian monasteries, monks were organized into groups of ten, each led by a decanus who reported to the abbot. The administrative structure of the monastery transferred to the cathedral, where the dean became the senior clergyman after the bishop.

English cathedral deans — the Dean of Canterbury, the Dean of Westminster — are still powerful ecclesiastical figures. The word entered English in the fourteenth century through Anglo-Norman deen, from Latin decanus. When universities adopted the term, they used it for the head of a faculty or school within the university. The dean of the law school, the dean of the medical school — each leads a division, just as the Roman decanus led a division of soldiers.

American universities expanded the dean's role beyond faculty governance. A dean of students handles discipline and student welfare. A dean of admissions manages who enters the university. A dean of diversity manages equity initiatives. The word dean has been attached to so many administrative functions that its original meaning — chief of ten — bears no relation to its modern scope. A dean of a large American university may oversee thousands of people.

The word has also entered informal English as a term of eminence: 'the dean of American sportswriters' means the most senior and respected figure in the field. The chief of ten became the chief of a faculty became the chief of a concept.