snow mold
noun
variants:
or snow rot
Definition of snow mold
1a
: a disease of cereals caused by a fungus (Calonectria graminicola) and characterized by abundant superficial white mycelium when the snow melts
b
: a similar disease especially of turf grasses caused by a fungus of the genera Typhula, Sclerotium or Fusarium
2
: a fungus causing a snow mold