canker
UK: ˈkæŋkə | US: ˈkæŋkər
n. 1. A destructive fungal or bacterial disease of plants, causing lesions or decay.
n. 2. An ulcerous condition, especially in the mouth (e.g., "canker sore").
n. 3. A persistent corrupting influence or source of deterioration.
The word "canker" traces back to Old English cancer (from Latin cancer, meaning "crab" or "ulcer"), influenced by Old French chancre. The Latin term metaphorically linked spreading ulcers to a crab's creeping motion. Over time, it narrowed to describe plant diseases and oral ulcers, retaining its core idea of progressive decay.
The rose bushes were infected with canker, causing their stems to wither.
She avoided spicy foods due to a painful canker sore.
Corruption is a canker that erodes trust in institutions.
The orchard had to remove trees to prevent the spread of canker.
Medieval texts often described moral decay as a "canker of the soul."