For words that only have 3 letters, there's no 4th letter. Such as with the word “include”, there isn't any a lot more letters afterwards and thus should be the word "add". The word “addict” is from the BIP39 wordlist however , you might have used “addi” for “addict”. Meticulously https://bookmarkswing.com/story20357608/a-review-of-bip39