Webster’s Revised Unabridged Dictionary · 1913
Champignon
Cham·pi′gnon (shăm·pĭn′yŭn; F. shäN′pē′nyôs′), n. [F., a mushroom, ultimately fr. L. campus field. See Camp.] (Bot.) An edible species of mushroom (Agaricus campestris).
Fairy ring champignon, the Marasmius oreades, which has a strong flavor but is edible.