For words that only have 3 letters, there is absolutely no 4th letter. For instance with the word “include”, there isn't any much more letters Later on and thus have to be the word "add". The word “addict” is while in the BIP39 wordlist but you might have utilised “addi” https://monobookmarks.com/story19516826/the-fact-about-bip39-seed-phrase-word-list-that-no-one-is-suggesting