usnīsa. One of the thirty-two marks (laksana) of a Buddha; originally a conical or flame-shaped tuft of hair on the crown of a Buddha, in later ages represented as a fleshly excrescence on the skull itself; interpreted as coiffure of flesh. In China it is low and large at the base, sometimes with a tonsure on top of the protuberance.

A Dictionary of Chinese Buddhist Terms, William Edward Soothill and Lewis Hodous