# hailstone number

> English word · Noun

## Definitions
1. Any number appearing in a sequence described by the Collatz conjecture.

## Etymology
The numbers are likened to hailstones because they "bounce" up and down before settling.

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