Quadrillions

Part of speech: noun

Definitions

1. A quantitative expression denoting a value of one thousand trillion, which is symbolized as 10^15, indicating a significantly large numerical magnitude with 15 zeros following the numeral one
2. An expression used in mathematics to describe a quantity equivalent to one followed by 15 zeros, specifically signifying one thousand trillion in a decimal system
3. A numerical term representing the quantity of one followed by fifteen zeros, which is one thousand trillion in count

Etymology: "Quadrillions" is the plural of "quadrillion," a noun for a thousand trillion, written as 10 to the power of 15. The word was formed in French from "quadri-," meaning four, joined to "-illion," the ending taken from "million." The pattern is deliberate: a million is 10 to the sixth power, and each new "-illion" name in the series steps up by a further factor of a thousand, so the names follow the ordinal count of thousands in the number. The "quadri-" element signals the fourth step in that series. Its name is built on the logic of the French system, where "quadrillion" sits after "trillion" (the third power of a million) and before "quintillion," with each name combining a Latin-derived numeral prefix and the same ending. That is why the word looks like a relative of "quadruple" and "quadrant," both drawing on the same Latin "quadr-" stem for four.