Source : Webster's Revised Unabridged Dictionary (1913)

Tous-les-mois \Tous`-les`-mois"\, n. [F., all the months, i.e.,
   every month.]
   A kind of starch with very large, oval, flattened grains,
   often sold as arrowroot, and extensively used for
   adulterating cocoa. It is made from the rootstocks of a
   species of {Canna}, probably {C. edulis}, the tubers of which
   are edible every month in the year.