carbuncle

carbuncle — noun

1. a large, painful area of infected skin where several boils have joined together,

1.nounC1
Definition

a large, painful area of infected skin where several boils have joined together, filled with pus, and needing medical treatment to heal

Example

The nurse said the carbuncle on Diego's neck needed to be drained by a doctor.

carbuncle + on [body part] for location

When Tomás ignored the red bump on his thigh, it grew into a large carbuncle within three days.

concrete scene: small bump ignored → large carbuncle

Common collocations
  • develop a carbuncle
  • drain a carbuncle
  • carbuncle on the neck
  • treat a carbuncle with antibiotics
Synonyms
  • boil

    a smaller, single infected hair follicle; less severe than a carbuncle

  • abscess

    a general pocket of pus anywhere in the body, not limited to the skin

Usage Note

A carbuncle is more serious than a boil — it involves a deeper infection with multiple pus-draining openings and often requires antibiotics or a minor surgical procedure.

Common Mistakes

He had a small carbuncle on his finger, like a pimple.
He had a small boil on his finger, like a pimple.
A carbuncle is always large and deep; a single small infected spot is a boil.

2. a dark red gemstone, especially a garnet that has been cut into a smooth rounded

2.nounC1
Definition

a dark red gemstone, especially a garnet that has been cut into a smooth rounded shape without facets, often used in jewellery

Example

The antique brooch was set with a large carbuncle surrounded by small diamonds.

collocation: carbuncle + set with / surrounded by

In Victorian times, carbuncles were very popular in rings and necklaces.

historical register: Victorian jewellery

Common collocations
  • carbuncle brooch
  • antique carbuncle ring
  • cabochon carbuncle
  • set with a carbuncle
Synonyms
  • garnet

    the modern name for most dark red gemstones formerly called carbuncles; more commonly used today

  • ruby

    a brighter red precious stone; distinct from carbuncle in colour and value

Usage Note

In modern English, 'carbuncle' as a gemstone term is quite rare; most people use 'garnet' instead. The word appears mainly in historical or antique jewellery descriptions.

Common Mistakes

She wore a bright green carbuncle ring.
She wore a dark red garnet ring.
Carbuncles are always red, never green. For green stones use 'emerald' or 'green garnet'.

Word family

  • carbuncular
    adjectiveC2
  • carbuncled
    adjectiveC2

Synonym discussion

Sense: noun/1

A carbuncle is a cluster of infected hair follicles that forms a single large, painful lump with several openings draining pus — essentially a group of boils joined together. A boil (also called a furuncle) is a single infected follicle: smaller, less painful, and usually heals on its own. An abscess is a broader term for any collection of pus caused by infection, which can form anywhere in the body (skin, tooth, internal organ), not just in hair follicles. For example: a dentist drains a gum abscess, but a surgeon drains a carbuncle on the back of the neck. All three require medical attention, but a carbuncle is the most severe because the infection reaches deeper tissue and often causes fever.

carbuncle ↗boil ↗abscessfuruncle

Common collocations

Nouns

Phrases

  • develop a carbuncle
  • drain a carbuncle
  • treat a carbuncle with antibiotics

Prepositions

Etymology

LatinOld FrenchEnglish

The word 'carbuncle' comes from Latin 'carbunculus', meaning 'a small red-hot coal' (from 'carbo' = coal). The two senses share the same visual idea: the swelling sense looks like a hot red coal under the skin, and the gemstone sense describes a dark red stone that glows like a coal ember. The word entered English through Old French 'carbuncle' around the 13th century, first referring to the gemstone, and later (by the 16th century) being applied to the skin infection because of its red, burning appearance.