Blackhead

Origin

From black + head.

Full definition of blackhead

Noun

1. (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.
2. A form of histomoniasis in poultry, characterized by cyanotic discoloration on the bird's head.
3. A scaup: a kind of duck.