ˈpithēəm noun
Etymology: New Latin, from Greek pythein to cause to rot + New Latin -ium — more at foul
1. capitalized : a genus of destructive root-parasitic fungi (family Pythiaceae) having filamentous sporangia, smooth-walled spherical oogonia, and stalked antheridia and including forms (as P. debaryanum ) that cause damping-off
2. -s : any fungus of the genus Pythium
pythium root necrosis