noun
1.
a. : any of various beans or showy seeds of tropical origin that are frequently carried by ocean currents to remote shores and often used as ornaments: as
(1) : the large chocolate-colored seed of a snuffbox bean used in poultices and as an emetic
(2) : oxeye bean
(3) : nicker nut
b. : a plant producing sea beans
2. : the hard flat rounded calcareous operculum of any of various mollusks (as those of the family Turbinidae)