Noun

1. An old English measure of weight, usually of wool, containing two stone or 28 pounds (13 kg).
   • Quotations

     1843: Seven pounds make a clove, 2 cloves a stone, 2 stone a tod, 6 1/2 tods a wey, 2 weys a sack, 12 sacks a last. [...] It is to be observed here that a sack is 13 tods, and a tod 28 pounds, so that the sack is 364 pounds. — The Penny Cyclopaedia of the Society for the Diffusion of Useful Knowledge, Volume 27, p. 202.

     1882: Generally, however, the stone or petra, almost always of 14 lbs., is used, the tod of 28 lbs., and the sack of thirteen stone. — James Edwin Thorold Rogers, A History of Agriculture and Prices in England, Volume 4, p. 209.

2. a fox, by extension, a crafty person.