---
title: "BIP39 Word #648: extend — Seed Phrase Mnemonic Word"
url: "https://bip39-phrase.com/bip39-word/extend/"
language: "en"
updated: "2026-10-19T00:00:00+00:00"
---

Word #648 01010000111 

# extend — BIP39 word #648

"**extend**" is word #648 of the 2048 words in the official BIP39 English wordlist, between [express](/bip39-word/express/) and [extra](/bip39-word/extra/). In a seed phrase it stands for the 11-bit value `01010000111`, decimal index 647\. 

/ɪksˈtɛnd/  · _verb:_ to make something longer or larger, or to reach out 

[Russian](/ru/ "The BIP39 wordlist with Russian translations"): расширять 

## Binary Representation

Five 1-bits and six 0-bits; 462 of the 2048 indexes have exactly five 1-bits.

One wrong bit turns it into (leftmost bit first):

[special](/bip39-word/special/)[axis](/bip39-word/axis/)[ill](/bip39-word/ill/)[domain](/bip39-word/domain/)[flight](/bip39-word/flight/)[female](/bip39-word/female/)[fancy](/bip39-word/fancy/)[faint](/bip39-word/faint/)[expire](/bip39-word/expire/)[expose](/bip39-word/expose/)[express](/bip39-word/express/) 

Position

Hex Index

0x287

4-Letter Prefix

exte

## About "extend" in BIP39

- "extend" has 6 letters, but the first four, **"exte"**, already identify it, because **"ext"** also begins [extra](/bip39-word/extra/).
- **"exte"** is unique only within the English list: it also begins extensif in the [French list](/french/) and externo in the [Portuguese list](/portuguese/), so a four-letter backup should say which list it uses.
- "extend" appears in one of the 24 official English [test vectors](https://github.com/trezor/python-mnemonic/blob/master/vectors.json) of BIP39: vector #21 (word 6 of 24). Every official vector passes the [checksum checker](/bip39-checksum-checker/), and [How BIP39 works](/how-bip39-works/) shows how the entropy turns into such words.

Official test vector #21

[all](/bip39-word/all/) [hour](/bip39-word/hour/) [make](/bip39-word/make/) [first](/bip39-word/first/) [leader](/bip39-word/leader/) extend [hole](/bip39-word/hole/) [alien](/bip39-word/alien/) [behind](/bip39-word/behind/) [guard](/bip39-word/guard/) [gospel](/bip39-word/gospel/) [lava](/bip39-word/lava/) [path](/bip39-word/path/) [output](/bip39-word/output/) [census](/bip39-word/census/) [museum](/bip39-word/museum/) [junior](/bip39-word/junior/) [mass](/bip39-word/mass/) [reopen](/bip39-word/reopen/) [famous](/bip39-word/famous/) [sing](/bip39-word/sing/) [advance](/bip39-word/advance/) [salt](/bip39-word/salt/) [reform](/bip39-word/reform/) 

## Word #648 in the Other 9 BIP39 Wordlists

[Czech](/czech/) kormidlo 

[French](/french/) éluder 

[Italian](/italian/) fessura 

[Japanese](/japanese/) こたつ 

[Korean](/korean/) 병아리 

[Portuguese](/portuguese/) dourado 

[Spanish](/spanish/) estilo 

[Traditional Chinese](/chinese-traditional/) 古 

[Simplified Chinese](/chinese-simplified/) 古 

## Similar Words — Check Carefully During Recovery

Words sharing the first three letters "ext":

[extra](/bip39-word/extra/) 

## More BIP39 Words Starting with "E"

[ #552 eager ](/bip39-word/eager/)[ #644 expire ](/bip39-word/expire/)[ #645 explain ](/bip39-word/explain/)[ #646 expose ](/bip39-word/expose/)[ #647 express ](/bip39-word/express/)[ #649 extra ](/bip39-word/extra/)[ #650 eye ](/bip39-word/eye/)[ #651 eyebrow ](/bip39-word/eyebrow/) 

[View all words starting with "E" ](/bip39-words/e/) 

## Seed phrase, key and recovery guides

- [Test Your Wallet Backup: A Self-Audit of Your Seed Phrase](/hack-own-crypto-wallet/)
- [EVM Address Format Explained: Structure & Usage](/format-evm-addresses/)
- [Is a Seed Phrase Case Sensitive? BIP39 Words vs Passphrase](/is-seed-phrase-case-sensitivity-really-important/)

[ Full BIP39 Wordlist ](/)