sum

Latin summus meant ‘highest’ (a meaning preserved in English summit (15^th c.), which is ultimately derived from it); it evolved from an earlier *supmus, a superlative form based on the stem of Latin super ‘above’ (source of English super). when the Romans counted up columns of figures they worked from the bottom upwards, and put the total on top – whence the use of the expression rēs summa, literally ‘highest thing’, for ‘total’. this was eventually shortened to summa, which reached English via Old French summe. other derivatives in English include consummate (15^th c.) and summary (15^th c.).