carbuncle

noun

1. Pathology. a painful circumscribed inflammation of the subcutaneous tissue, resulting in suppuration and sloughing, and having a tendency to spread somewhat like a boil, but more serious in its effects.
2. a gemstone, especially a garnet, cut with a convex back and a cabochon surface.
3. Also called London brown. a dark grayish, red-brown color.
4. Obsolete. any rounded red gem.

adjective

5. having the color carbuncle.

noun

1. an extensive skin eruption, similar to but larger than a boil, with several openings: caused by staphylococcal infection
2. a rounded gemstone, esp a garnet cut without facets
3. a dark reddish-greyish-brown colour

n.

early 13c., “fiery jewel,” from Old North French carbuncle (Old French charbocle, charboncle) “carbuncle-stone,” also “carbuncle, boil,” from Latin carbunculus “red gem,” also “red, inflamed spot,” literally “a little coal,” from carbo (genitive carbonis) “coal” (see carbon). Originally of rubies, garnets, and other red jewels; in English the word was applied to tumors from late 14c.

n.

1. A deep-seated pyogenic infection of several contiguous hair follicles, with formation of connecting sinuses, often preceded or accompanied by fever, malaise, and prostration.
2. anthrax