zetta- [ZE tuh] +

(Latin: septo-, "seven"; a decimal prefix [1021] used in the international metric system for measurements)

This prefix is used in the metric [decimal] system as sextillion [U.S.] or quadrillionfold [U.K.], 1021 [1 000 000 000 000 000 000 000]. The metric symbol is Z.
zettajoule (ZJ)
Approximately the world energy production per year.
zettaliter (ZL)
One zettaliter is estimated to be the volume of the Pacific Ocean.
zettameter (Zm)
One zettameter is said to be approximately the radius of the Milky Way galaxy.

Related "metric" families: yotta; exa; peta; tera; giga; mega; kilo; hecto; deka; deci; centi; milli; micro; nano; pico; femto; atto; zepto; yocto.