Borrowed from Maldivian Dhivehi 'atholhu,' the word for a ring of islands, via Portuguese colonial contact.
A ring-shaped coral reef or chain of islands enclosing a shallow lagoon.
From Dhivehi 'atholhu,' the administrative term for island groups in the Maldives. Borrowed into English via Portuguese colonial contact in the Indian Ocean. Darwin's 1842 theory of atoll formation by subsiding volcanic islands made the word widely known. Key roots