Bun"yon, Bun"ion (?), n. [Cf. Prov. E. bunny a small swelling, fr. OF. bugne, It. bugna, bugnone. See Bun.] Med.
An enlargement and inflammation of a small membranous sac (one of the bursae muscosae), usually occurring on the first joint of the great toe.
© Webster 1913.