For words that only have three letters, there's no 4th letter. By way of example with the word “increase”, there won't be any a lot more letters Later on and therefore should be the word "include". The word “addict” is within the BIP39 wordlist but you would have utilised “addi” https://bookmarkgenious.com/story18934240/considerations-to-know-about-bip39-word-list-pdf