zetta-

Meanings

1. In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 10²¹ (a short scale sextillion or long scale trilliard). Symbol: Z

Etymology

Coined with Latin septem and Ancient Greek ἑπτά (heptá, “seven”) in mind, for the seventh order of 10³. The consonants pt are reduced to tt; the initial z was chosen instead of s to avoid confusion with s for second.