For words that only have 3 letters, there's no 4th letter. Such as with the word “include”, there aren't any additional letters Later on and thus should be the word "add". The word “addict” is in the BIP39 wordlist however , you would have used “addi” for “addict”. The best https://tripsbookmarks.com/story19190996/the-ultimate-guide-to-bip39-seed-phrase-mnemonics-generator