For words that only have 3 letters, there isn't any 4th letter. One example is with the word “include”, there are no extra letters afterwards and thus have to be the word "incorporate". The word “addict” is inside the BIP39 wordlist however, you might have utilized “addi” for “addict”. The https://bookmarkstumble.com/story20716836/5-simple-techniques-for-bip39-seed-phrase