Definitions for earthstarˈɜrθˌstɑr
Random House Webster's College Dictionary
a fungus of the genus Geaster, having an outer covering that splits into the form of a star.
Origin of earthstar:
any fungus of the family Geastraceae; in form suggesting a puffball whose outer peridium splits into the shape of a star
A type of puffball, of genus Geastrum, whose surface splits open in a star-shaped form
a curious fungus of the genus Geaster, in which the outer coating splits into the shape of a star, and the inner one forms a ball containing the dustlike spores