What does theriac mean?
Theriac is a rare historical noun for a medicinal compound believed to counteract poison. Its best-known historical form was Venetian theriac, a costly preparation associated with spices, herbal ingredients, and honey and carried on long voyages as protection against poison and infectious disease. In older writing, theriac could also stand more broadly for an antidote or potent remedy. The word is no longer a standard term in medicine; its chief modern presence is in historical texts and discussions of early pharmacology, where it evokes attempts to create a universal safeguard against deadly substances. The expression Venetian treacle reflects the preparation’s reputation and gives the word a connection with treacle, although modern treacle is simply a syrup and should not be treated as a direct synonym. Theriac is therefore chiefly interesting as a surviving piece of medical vocabulary rather than as a recommendation or a currently recognized drug.
nounA historical medicinal preparation believed to counteract poison, especially the compound known as Venetian theriac. The term is now chiefly confined to historical and literary usage.
- A medicinal compound or remedy believed to neutralize poison.
- A costly historical preparation used as a prophylactic against poison and infectious disease.
"The physician administered theriac in the hope that it would neutralize the poison."
"The apothecary prepared a batch of theriac from a complex mixture of ingredients."
"Venetian theriac was highly valued on long voyages as protection against disease and poisoning."
The regular plural is rare and is used chiefly when referring to different formulations or preparations.
"The physician compared several theriacs before selecting one for the patient."
For centuries, theriac was carried as a supposed shield against poison—a vivid reminder of humanity’s ambition to create a universal antidote.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does theriac come from?
Theriac entered Middle English from Latin theriaca, a feminine adjective meaning “of or concerning wild beasts” that was also used for antidotes. Latin borrowed the term from Greek theriakē, meaning “antidote,” from therion, “wild beast,” reflecting the ancient belief that a remedy prepared from the flesh or bodily materials of an animal could neutralize poison. The best-known medieval preparation was Venetian theriac, which helped give the word its enduring association with supposed protection against poison and plague.
Related word forms
How theriac is actually used
Theriac is archaic and literary rather than a standard modern medical term. In older writing it may denote an antidote or general remedy, not a specific contemporary drug.
Easily confused with theriac
Venetian treacle was a historical preparation associated with theriac and its reputation as an antidote, whereas modern treacle is simply a syrup.
Theriac denotes a historical poison antidote, while thoracic means relating to the chest or thorax.