# Cassini oval

> English word · Noun

## Definitions
1. A plane curve defined as the set (or locus) of points in the plane such that the product of the distances to two fixed points is constant (related to an ellipse, for which the sum of the distances is constant).

## Etymology
Named after the astronomer Giovanni Domenico Cassini, who studied them in 1680.

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