# Heawood conjecture

> English word · Proper noun

## Definitions
1. A conjecture (proven in 1968) that gives a lower bound for the number of colors that are necessary for graph coloring on a surface of a given genus.

## Etymology
Formulated in 1890 by Percy John Heawood.

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