'atoll' originates from Dhivehi (Maldivian), specifically the word 'atholhu', where the root meant 'ring-shaped reef' or 'reef encircling a lagoon'.

'atoll' was borrowed into European languages from Dhivehi (or via sailors' reports from the Maldives) in the 17th–18th centuries as maritime explorers recorded the local term 'atholhu'; over time the form was adapted into English as 'atoll'.

Initially it meant a local name for a 'ring-shaped coral reef or island' and this core meaning has remained largely unchanged in modern usage.