The quality or state of being cankered; corruption, decay, or the condition of being affected by canker disease.
Formed by adding the noun-forming suffix '-ness' to 'cankered'. This allowed the abstraction of the quality of being diseased or corrupted into a countable concept.
The fact that English has both 'cankeredness' and 'cankery' shows writers experimenting with different ways to name the abstract idea of corruption—a sign of how actively language was being shaped in early modern times.
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