# Sagan

> English word · Proper noun · IPA /ˈseɪɡən/ · frequency rank #29,822

## Definitions
1. A surname.

## Etymology
The unit is derived from the phrase "billions and billions (of stars)", erroneously attributed to the American astronomer Carl Sagan. The lower bound of such a number must be two billion plus two billion, or four billion. Johnny Carson popularized the phrase through his occasional impersonation of Sagan throughout his career.

## Easily confused with
- **san** (https://plainspell.com/en/vs/sagan-vs-san)
- **sign** (https://plainspell.com/en/vs/sagan-vs-sign)
- **sean** (https://plainspell.com/en/vs/sagan-vs-sean)
- **scan** (https://plainspell.com/en/vs/sagan-vs-scan)
- **span** (https://plainspell.com/en/vs/sagan-vs-span)
- **stan** (https://plainspell.com/en/vs/sagan-vs-stan)
- **Sara** (https://plainspell.com/en/vs/sagan-vs-sara)
- **swan** (https://plainspell.com/en/vs/sagan-vs-swan)
- **sage** (https://plainspell.com/en/vs/sagan-vs-sage)
- **shan** (https://plainspell.com/en/vs/sagan-vs-shan)
- **Sega** (https://plainspell.com/en/vs/sagan-vs-sega)
- **SATA** (https://plainspell.com/en/vs/sagan-vs-sata)
- **sala** (https://plainspell.com/en/vs/sagan-vs-sala)
- **sian** (https://plainspell.com/en/vs/sagan-vs-sian)
- **Suga** (https://plainspell.com/en/vs/sagan-vs-suga)
- **sawn** (https://plainspell.com/en/vs/sagan-vs-sawn)
- **saya** (https://plainspell.com/en/vs/sagan-vs-saya)
- **sugar** (https://plainspell.com/en/vs/sagan-vs-sugar)
- **Sarah** (https://plainspell.com/en/vs/sagan-vs-sarah)
- **Susan** (https://plainspell.com/en/vs/sagan-vs-susan)

## Common misspellings (7)
`asgan`, `saagn`, `sagann`, `saggan`, `sagna`, `sgaan`, `ssagan`

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