# lake of Wada

> English word · Noun

## Definitions
1. Any of three disjoint connected open sets of the plane or open unit square with the counterintuitive property that they all have the same boundary.

## Etymology
Calque of Japanese 和田の湖. Introduced by Kunizo Yoneyama (in 1917), who credited the discovery to Takeo Wada.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/lake-of-wada