blackhead

 

black + head

blackhead (countable and uncountable, plural blackheads)

1. (countable, medicine) A comedo, a skin blemish, a type of acne vulgaris, where a pore becomes clogged with a dark, hard, cheesy keratin-filled substance forming a hard black "head" on the skin's surface.

   Coordinate term: whitehead

   • 1972, “Thick As A Brick”, Ian Anderson (lyrics), performed by Jethro Tull:

     See there! A son is born
     And we pronounce him fit to fight
     There are blackheads on his shoulders
     And he pees himself in the night.

   • 2020, Brandon Taylor, Real Life, Daunt Books Originals, page 215:

     Wallace sees a cluster of tiny blackheads at the corner of his nose.

2. (uncountable) A form of histomoniasis in poultry, characterized by cyanotic discoloration on the bird's head.
3. (countable) A scaup: any of various ducks of the genus Aythya.

• blackheaded (second sense)

•   blackhead on Wikipedia.Wikipedia
•   Blackhead in the 1920 edition of Encyclopedia Americana.