Home › Words › Y › yellowbillyellowbillyellowbill · noun — ceuthmochares aereus, an African cuckoo with a heavy yellow bill.Definition from Wiktionary (CC BY-SA 3.0).EtymologyBahuvrihi compound of yellow + billnounCeuthmochares aereus, an African cuckoo with a heavy yellow bill.Definitions & examples from Wiktionary (CC BY-SA 3.0).