'archimandrite' originates from Greek, specifically the word 'archimandritēs', where 'archi-' meant 'chief' and 'mandra' meant 'fold, enclosure (originally a sheepfold, later used of a monastery).

'archimandritēs' passed into Medieval/Church Latin as 'archimandrita' and then entered English (via ecclesiastical Latin and other European languages) as 'archimandrite'.

Initially it meant 'chief of the fold/enclosure' (literally a chief of a fold), but over time it evolved to mean 'head of a monastery' or a senior monastic superior.