For words that only have three letters, there is no 4th letter. One example is with the word “include”, there isn't any far more letters afterwards and so have to be the word "add". The word “addict” is from the BIP39 wordlist however you would've employed “addi” for “addict”. Artwork https://bookmarklogin.com/story18946878/5-simple-techniques-for-bip39-word-list-pdf