For words that have only three letters, there isn't a 4th letter. One example is with the word “increase”, there won't be any a lot more letters Later on and therefore have to be the word "add". The word “addict” is within the BIP39 wordlist however , you would have https://ztndz.com/story21870374/the-fact-about-valid-bip39-seed-phrase-that-no-one-is-suggesting