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1.
Theoretical limit of weight based on the maximum amount of mass that could be considered to still be within the bounds of earths normal gravity.

Impossible to achieve as adding that much mass would alter the Earths properties to the point of altering the gravity on Earth.
Covering the entire Earth's surface with 62 miles of super dense substance (62 miles at sea level, adjust accordingly)

The weight of said substance would be considered a Fucktonne
by Proffesor F Wolf July 20, 2008
 
2.
7. When using fucktonne as a reference to a quantity. Such quantitiy would simply refer to the number 7.
There are a fucktonne of hot chicks in this bar.
There are seven hot chicks in this bar.
by Fucktonne=7 January 01, 2011