Cankerwort

Part of speech: noun

Definitions

1. A plant formerly thought to have healing properties against canker or similar fungal infections
2. An herb traditionally used as a remedy for canker and related diseases affecting plants or flesh
3. A plant historically believed to treat or prevent the spread of canker disease

Etymology: Cankerwort is a plant name built from two plain English parts. "Canker" is the older word, and in its earliest English uses it meant a sore or ulcer, and later a disease that eats away at a plant or animal. "Wort" is the Old English word for a plant or herb, still visible in names like St John's wort and mugwort. Put together, the name was given to a plant believed to cure the sores and ulcers that "canker" described, a common medicinal logic in old herb names. The compound is transparent in a way many plant names are not, so its meaning follows directly from its parts. The "canker" half had already shifted from a physical sore to the sense of something that spreads destructively, which is why the same word later appears in phrases about corruption and decay, while the plant name stayed rooted in its original medicinal use.