 zak

a Dutch unit of volume, equals to the hectoliter (100 liters), 26.417 U.S.
gallons, 21.999 British imperial gallons, or 3.5315 cubic feet. This is a
metric version of the British sack.
 zentner

a traditional German unit of weight or mass, comparable to the traditional
quintal and to the English hundredweight. Originally the zentner was equal to
100 pfund, or German pounds. The zentner was redefined in metric system
to equal to exactly 50 kilograms, which is about 110.231 pounds.
 zepto

a metric prefix denoting 10^{21} (one sextillionth), the prefix is
derived from the Latin septem , meaning 7, for the seventh prefix (n =
7 in 10^{3n}) in the SI system of metric prefixes.
 zetta

a metric prefix denoting 10^{21} (one sextillion). Similar to other
profix like yotta, zetta was coined to parallel the prefix zepto.
 zoll

the traditional German inch, equal to 1/12 fuss (the German
foot). In Switzerland, it is now considered a metric unit equal to 3
centimeters (1.1811 inches).
