For words that only have three letters, there is not any 4th letter. As an example with the word “add”, there isn't any a lot more letters Later on and thus has to be the word "incorporate". The word “addict” is in the BIP39 wordlist however, you would've utilized “addi” https://monobookmarks.com/story18865425/top-latest-five-bip39-words-urban-news