For words that only have three letters, there isn't any 4th letter. For instance with the word “include”, there are no additional letters afterwards and therefore should be the word "increase". The word “addict” is inside the BIP39 wordlist however , you would have employed “addi” for “addict”. A seed https://bookmarkbooth.com/story18825345/considerations-to-know-about-bip39-word-list-pdf