Main Entry: black·head

Pronunciation: \ˈblak-ˌhed\

Function: noun

Date: circa 1837

1 : a small plug of sebum blocking the duct of a sebaceous gland especially on the face
2 : a destructive disease of turkeys and related birds caused by a protozoan (Histomonas meleagridis) that invades the intestinal ceca and liver
3 : a larval clam or mussel attached to the skin or gills of a freshwater fish