Source : Webster's Revised Unabridged Dictionary (1913)

Tonne \Tonne\, n. [F.]
   A metric ton.

Tonne \Tonne\, n.
   A tun. [Obs.] --Chaucer.

Source : WordNet®

tonne
     n : a unit of weight equivalent to 1000 kilograms [syn: {metric
         ton}, {MT}, {t}]