Source : Webster's Revised Unabridged Dictionary (1913)

Treacle \Trea"cle\ (tr[=e]"k'l), n. [OE. triacle a sovereign
   remedy, theriac, OF. triacle, F. th['e]riaque (cf. Pr.
   triacla, tiriaca, Sp. & It. triaca, teriaca), L. theriaca an
   antidote against the bite of poisonous animals, Gr. ?, fr. ?
   of wild or venomous beasts, fr. qhri`on a beast, a wild
   beast, dim. of qh`r a beast. Cf. {Theriac}.]
   1. (Old Med.) A remedy against poison. See {Theriac}, 1.

            We kill the viper, and make treacle of him. --Jer.
                                                  Taylor.

   2. A sovereign remedy; a cure. [Obs.]

            Christ which is to every harm treacle. --Chaucer.

   3. Molasses; sometimes, specifically, the molasses which
      drains from the sugar-refining molds, and which is also
      called {sugarhouse molasses}.

   Note: In the United States molasses is the common name; in
         England, treacle.

   4. A saccharine fluid, consisting of the inspissated juices
      or decoctions of certain vegetables, as the sap of the
      birch, sycamore, and the like.

   {Treacle mustard} (Bot.), a name given to several species of
      the cruciferous genus {Erysimum}, especially the {E.
      cheiranthoides}, which was formerly used as an ingredient
      in Venice treacle, or theriac.

   {Treacle water}, a compound cordial prepared in different
      ways from a variety of ingredients, as hartshorn, roots of
      various plants, flowers, juices of plants, wines, etc.,
      distilled or digested with Venice treacle. It was formerly
      regarded as a medicine of great virtue. --Nares.

   {Venice treacle}. (Old Med.) Same as {Theriac}, 1.