# four-color problem

[fawr-kuhl-er, fohr-]

- the problem, solved in 1976, of proving the theorem that any geographic map can be colored using only four colors so that no connected countries with a common boundary are colored the same color.

## Origin of four-color problem^{}

First recorded in 1875–80

Also called four-color theorem.

Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018