For words that only have three letters, there's no 4th letter. For instance with the word “increase”, there aren't any extra letters Later on and thus needs to be the word "incorporate". The word “addict” is in the BIP39 wordlist however, you would have utilised “addi” for “addict”. Try to https://exactlybookmarks.com/story18789240/the-2-minute-rule-for-bip39-all-words