four-color problem

[fawr-kuhl-er, fohr-]

noun Mathematics.

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.

Nearby words

  1. four-banger,
  2. four-by-four,
  3. four-by-two,
  4. four-channel,
  5. four-color,
  6. four-color process,
  7. four-colour,
  8. four-corners,
  9. four-cycle,
  10. four-deal bridge

Origin of four-color problem

First recorded in 1875–80

Also called four-color theorem. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019