Definitions

1. noun

A circular or oval-shaped coral reef or island that forms a ring or ellipse around a central lagoon, especially in the Pacific Ocean.

“The researchers studied the unique ecosystem of the pseudatoll, which was formed by coral growth over thousands of years.”

2. noun

A type of ring-shaped island or reef that is not a true atoll.

“The pseudatoll in the Indian Ocean was initially thought to be a typical atoll, but further research revealed its distinct characteristics.”