1. A blister beetle, especially the Spanish fly (Lytta vesicatoria), historically used in medicine and as a poison.
Usage: technical; historical; also called Spanish fly
2. A preparation or extract made from the cantharis beetle, formerly used in folk medicine and veterinary practice.
Usage: archaic; medical history

Examples

• The cantharis beetle contains a toxic compound called cantharidin.
• Medieval physicians sometimes prescribed cantharis as a treatment, though it was dangerous.
• Cantharis was historically used in veterinary medicine to treat certain conditions in horses.
• The bright green cantharis is easily recognized by its metallic sheen.
• Ancient texts mention cantharis as an ingredient in various remedies.