carbuncle

noun

1. 1

   A deep-red or fiery colored garnet or other dark red precious stone, especially when cut cabochon.

2. 2

   A charge or bearing supposed to represent the precious stone, with eight sceptres or staves radiating from a common centre; an escarbuncle.

3. 3

   An abscess larger than a boil, usually with one or more openings draining pus onto the skin. It is usually caused by bacterial infection.

4. 4

   An unpopular or ugly building; an eyesore.