For words that only have three letters, there isn't a 4th letter. By way of example with the word “include”, there won't be any a lot more letters afterwards and thus needs to be the word "increase". The word “addict” is inside the BIP39 wordlist however, you might have utilized https://bookmarkspiral.com/story18837509/the-ultimate-guide-to-bip39-seed-phrase-mnemonics-generator