Septem

Septem is the Latin word for the number seven. In Classical Latin it functions as a cardinal numeral and is used in a range of expressions to denote seven units, such as septem dies (seven days) or septem milia (seven thousand). It also appears in various compound terms and set phrases that denote quantity or time.

Etymology and cognates: Septem derives from the Proto-Italic form *septem, which in turn comes from the Proto-Indo-European root *sept- meaning seven. It has descendants in many languages, including Greek hepta, Sanskrit sapta, and the modern Romance languages—Italian sette, Spanish siete, French sept, Portuguese sete. The English prefix sept- and the month name September ultimately echo this same root; September was named for being the seventh month in the early Roman calendar, a position altered by later calendar reforms.

Historical usage: In ancient Rome, the form appears in compound titles such as septemviri, literally "a board of seven" (for example, the septemviri sacris faciundis, a college responsible for certain sacred rites). The word also appears in liturgical and legal Latin and in the Latin Bible (Vulgate) to render the number seven.

Modern relevance: Today, septem is chiefly a linguistic and historical term. It remains a common reference point in discussions of Latin grammar, Roman history, and the etymology of calendar names and numerical roots.

See also: September, Latin numerals, Romance language cognates, septemviri.