\The"ri*ac\, Theriaca \The*ri"a*ca\, n. [L. theriaca an
antidote against the bite of serpents, Gr. ?: cf. F.
th['e]riaque. See {Treacle}.]
1. (Old Med.) An ancient composition esteemed efficacious
   against the effects of poison; especially, a certain
   compound of sixty-four drugs, prepared, pulverized, and
   reduced by means of honey to an electuary; -- called also
   {theriaca Andromachi}, and {Venice treacle}.
2. Treacle; molasses. --British Pharm.

\The"ri*ac\, Theriacal \The*ri"a*cal\, a. [Cf. F.
th['e]riacal.]
Of or pertaining to theriac; medicinal. ``Theriacal herbs.''
--Bacon.