Entry 1 sense Webster, 1913 Ringbill · Ring·bill · IPA 01 n. The ring-necked scaup duck; -- called also ring-billed blackhead. See Scaup. 1. The ring-necked scaup duck; -- called also ring-billed blackhead. See Scaup.(Zool.) Also: ring-billed blackhead See: Scaup