[fairy ring] n [fr. the folk belief that such rings were dancing places of the fairies] (1599) 1: a ring of basidiomycetous mushrooms produced at the periphery of a body of mycelium which has grown outward from an initial growth point; also: a ring of luxuriant vegetation esp. when associated with these mushrooms
2: a mushroom (esp. Marasmius oreades) that commonly grows in fairy rings