One of the mysteries of the English language finally explained.
Definition of Tuvalu in US English:
Tuvalu
proper noun
A country in the southwestern Pacific Ocean consisting of a group of nine main islands, formerly called the Ellice Islands; population 10,000 (estimated 2015); official languages, English and Tuvaluan (local Austronesian language); capital, Funafuti. The islands formed part of the British colony of the Gilbert and Ellice Islands but separated from the Gilberts after a referendum in 1975. Tuvalu became independent within the Commonwealth of Nations in 1978.