- any of various black-headed birds, esp. the scaup duck
- a black-tipped plug of dried fatty matter in a pore of the skin
- ☆ an infectious disease of the intestines and liver of turkeys, chickens, etc. caused by a protozoan (Histomonas meleagridis) and characterized by a dark, discolored comb
- the parasitic larva of a freshwater mussel (family Unionidae) encysted in the gills, etc. of a fish
See blackhead in American Heritage Dictionary 4
- Medicine A plug of keratin and sebum within a hair follicle that is blackened at the surface. Also called comedo.
- An infectious disease of turkeys and some wildfowl that is caused by a protozoan (Histomonas meleagridis) and results in lesions of the intestine and liver. Also called enterohepatitis, histomoniasis, infectious enterohepatitis.
- Any of various birds, such as the scaup, with dark head markings.
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