For words that have only three letters, there isn't any 4th letter. For example with the word “add”, there isn't any far more letters Later on and therefore has to be the word "increase". The word “addict” is while in the BIP39 wordlist however you would've utilized “addi” for “addict”. https://bookmarkwuzz.com/story18942399/a-review-of-bip39-passphrase