winter mushroom: an edible agaric that is available in early spring or late fall when few other mushrooms are; has a viscid smooth orange to brown cap and a velvety stalk that turns black in maturity and pallid gills; often occur in clusters
agaric: a saprophytic fungus of the order Agaricales having an umbrellalike cap with gills on the underside
association: (chemistry) any process of combination (especially in solution) that depends on relatively weak chemical bonding