For words that have only 3 letters, there is not any 4th letter. By way of example with the word “increase”, there isn't any additional letters Later on and thus should be the word "increase". The word “addict” is from the BIP39 wordlist however, you might have utilised “addi” for https://userbookmark.com/story18869283/a-review-of-bip39-passphrase