Comedone is the technical term for a blackhead (comedo for a single blackhead).
Originating in the middle 19th century, from the Latin, meaning literally "glutton" from the word "comedere" meaning "to eat up" ("com" meaning "altogether" and "edere" the verb "to eat."
The former use for the term described parasitic worms.
The term likely alludes to the worm-like congealed matter that emerges when a blackhead is squeezed.
Open pores (made visible by distension from oxidized cellular wastes and comedogenic cosmetics) may behave similarly.