E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
means London weight. London used to be called Troy-novant. (See above.) The general notion that the word is from Troyes, a town of France, and that the weight was brought to Europe from Grand Cairo by crusaders, is wholly untenable, as the term Troy Weight was used in England in the reign of Edward the Confessor. Troy weight is old London weight, and Avoirdupois the weight brought over by the Normans. (See AVOIRDUPOIS.)