The story
Named after German mathematician Richard Dedekind (1831–1916), who introduced the concept (although a similar construction was used in Euclid's Elements to define proportional segments).
Etymology from Wiktionary, CC BY-SA 4.0.
Dedekind cut
Today it means: Any partition of the set of rational numbers into non-empty sets A and B such that all elements of A are less than all elements of B and A contains no greatest element; intended as a construction of a real number. Full definition →