casual
/ˈkæʒjʊəl/
Binary Representation
11-bit index: 00100011101 (decimal 285)
Position
#286 of 2048
Hex Index
0x11D
4-Letter Prefix
casu
About "casual" in BIP39
"casual" is the #286 word
in the official BIP39 English mnemonic wordlist. It is encoded as the 11-bit binary value
00100011101
(decimal index 285), placing it at the 14% mark of the full 2048-word list.
The 4-letter prefix "casu" uniquely identifies this word among all 2048 entries. At 6 characters, it falls in the typical length range for BIP39 words, balancing readability with distinctiveness during manual wallet recovery.
Positioned in the first quarter of the wordlist (index 285), "casual" starts with "C" — a letter group containing 186 words total. It is word #33 within that group. Words early in the list have lower binary values with more leading zeros, which can be relevant when analyzing raw entropy data.
In a 12-word seed phrase, each word encodes 11 bits of entropy. The probability of "casual" appearing in any specific position of a randomly generated phrase is 1 in 2048 (≈ 0.049%). A complete 24-word phrase encodes 256 bits of entropy, providing security equivalent to a key space of approximately 1.16 × 10⁷⁷ — far beyond the reach of brute-force attacks.
Word #286 in the Other 9 BIP39 Wordlists
Every official BIP39 wordlist has exactly 2048 entries, so index 285 encodes the same 11-bit value
(00100011101) in every language.
A wallet configured for one of these languages would use this word instead of "casual":