Definition:Avoirdupois/Ton/Linguistic Note

Linguistic Note on Ton
The word ton derives from the same source as the word tun or tunne, a cask hold $216$ gallons of wine.

The word ton is pronounced tun.

In colloquial language, the word ton is in common use as a rhetorical flourish for a weight too heavy to be easily managed, for example:
 * This suitcase weighs a ton!

It is also motoring slang, at least in Britain, for $100$ miles per hour:
 * Took the beamer up to a ton going up the M6 last night, good job there weren't no fuzz around.

The usage is commonly seen as doing the ton, meaning driving at $100$ miles per hour.