ˈopen-bill
A bird of the genus Anastomus, allied to the Stork, found in Africa and Asia; so called because the mandibles of its bill when shut are in contact only at the ends, leaving an open space in the middle.
| 1837 Swainson Nat. Hist. Birds II. 174 The tufted umbre..is obviously allied to the open-bills (Anastomus, Ill.), a singular form, remarkable for a thick and very powerful bill gaping in the middle. 1894 Newton Dict. Birds s.v. |