For words that have only three letters, there isn't any 4th letter. One example is with the word “include”, there aren't any a lot more letters Later on and therefore has to be the word "insert". The word “addict” is during the BIP39 wordlist but you might have utilised “addi” http://jaspermuxp089.yousher.com/from-mnemonics-to-security-comprehending-bip39-passphrases-and-their-significance-in-copyright