Word #2048 11111111111

zoo — BIP39 word #2048

"zoo" is the last of the 2048 words in the official BIP39 English wordlist, right after zone. In a seed phrase it stands for the 11-bit value 11111111111, decimal index 2047.

/zuː/ · noun: a place where wild animals are kept for people to see

Russian: зоопарк

Binary Representation

All eleven bits are 1: it is the only index without a 0-bit.

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

lend say that useful wave winner worth year youth zero zone

Position

#2048 of 2048

Hex Index

0x7FF

4-Letter Prefix

zoo

About "zoo" in BIP39

It takes all three letters to identify "zoo": "zo" also begins zone. Three letters are enough for only 604 of the 2048 words.
"zoo" appears in three of the 24 official English test vectors of BIP39: vectors #4 (words 1–11 of 12), #8 (words 1–17 of 18) and #12 (words 1–23 of 24). Every official vector passes the checksum checker, and How BIP39 works shows how the entropy turns into such words.

Official test vector #4

zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo wrong