# halmos

> English word · Noun

## Definitions
1. The symbol “∎” marking the end of a proof.

## Etymology
Named after Hungarian-born US mathematician Paul Halmos (1916-2006) who first used it in mathematics, after seeing it marking the end of articles in magazines.

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