1) a gangrene, a disease by which any part of the body suffering from inflammation becomes so corrupted that, unless a remedy be seasonably applied, the evil continually spreads, attacks other parts, and at last eats away the bones
Part of Speech: noun feminine
From γραίνω grainô (to gnaw); an ulcer ("gangrene"): - canker.
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root γάγγραινα; click on the second column to search for that grammatical form of the root γάγγραινα; click on the third column to search for that word and grammatical form; click on the total to search for the root γάγγραινα.