seven [OE] Seven days of the week, seven deadly sins, seven dwarfs, seven wonders of the world, the Magnificent Seven…the number seven crops up again and again in history and culture. The word is from the same ancient root as Latin septem and Greek hepta ‘seven’—septem is the source of September [OE], originally the seventh month of the Roman year, and of septet [E19th], whereas hepta is found in words such as heptagon [M16th] ‘seven angled’, and heptathlon [1970s] combined with athlon ‘contest’.