to square the circle
Preserved but no longer current.
To attempt an impossi- bility. The allusion is to the impossibility of exactly determining the precise ratio between the diameter and the circumference of a circle, and thus constructing a circle of the same area as a given square. Popularly it is 3-14159 . . . the next decimals would be 26537, but the numbers would go on ad infinitum.
Era: ca. 1898 (Victorian)
Sources & notes
Reproduced from Brewer’s Dictionary of Phrase and Fable (1898 edition, public domain; archive.org, retrieved 2026-07-31; OCR text, minor errors possible). Reflects the scholarship and attitudes of its era.
Common questions
What does “to square the circle” mean?
To attempt an impossi- bility. The allusion is to the impossibility of exactly determining the precise ratio between the diameter and the circumference of a circle, and thus constructing a circle of the same area as a given square. Popularly it is 3-14159 . . . the next decimals would be 26537, but the numbers would go on ad infinitum.
Is “to square the circle” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.