Polyporus \Po*lyp"o*rus\, n.; pl. {Polypori}. [NL., fr. Gr. poly`s many + ? a pore.] (Bot.) A genus of fungi having the under surface full of minute pores; also, any fungus of this genus. [1913 Webster] Note: {Polyporus fomentarius} was formerly dried and cut in slices for tinder, called amadou. {Polyporus betulinus} is common in America, and forms very large thick white semicircular excrescences on birch trees. Several species of {Polyporous} are considered edible. [1913 Webster]