# cardioid

> English word · Noun

## Definitions
1. An epicycloid with exactly one cusp; the plane curve with polar equation ρ=1+ cos ,θ - approximately heart-shaped

## Etymology
By surface analysis, cardi- + -oid.

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