5 letters · 5 points in Scrabble
noun an island consisting of a circular coral reef surrounding a lagoon
originBorrowed from Portuguese atol, from Dhivehi އަތޮޅު (atoḷu), possibly from Prakrit *𑀲𑀁𑀢𑀻𑀞 (*saṃtīṭha), from Sanskrit *संतीर्थ (*saṃtīrtha, “level ford”). The traditional etymology from Persian آبتل (âb-tal, “water-hillock”) is unlikely.
Etymology from Wiktionary, CC BY-SA 3.0