Septuplet

Part of speech: noun

Definitions

1. A set of seven related items, particularly seven notes played in the time normally given to six ; one of seven babies delivered together from a single pregnancy
2. A grouping of seven, most often a cluster of seven notes sounded within the span of six ; any one of seven infants born at the same time to one mother
3. Seven linked things considered as a unit, such as a musical figure of seven evenly spaced notes ; a child who is one of seven siblings born in a single birth

Etymology: Septuplet is a plain formation, and its parts are old. The Latin "septem" meant "seven," and the Latin "-plus" (as in "duplus," "triplus") meant "-fold," so "septuplus" meant "seven times over." English took this as "septuple," an adjective for something seven-fold, and then added the diminutive suffix "-et," the same ending found in "booklet" or "piglet," to name a group of seven. The "-et" ending was used to make "duplet," "triplet," and "quadruplet" in the same way, so "septuplet" follows an established pattern. The Proto-Indo-European root behind "septem" is also the source of "seven" in English and of many other seven-words across the Indo-European languages, so the number and the word share a very old ancestry. The Proto-Afroasiatic and Proto-Semitic roots shown in the lineage belong to a separate, much older layer of reconstruction and do not bear directly on the English word's formation.