For words that have only three letters, there's no 4th letter. For instance with the word “include”, there are no additional letters afterwards and therefore have to be the word "incorporate". The word “addict” is in the BIP39 wordlist however you would've utilised “addi” for “addict”. Locating one particular missing https://bookmarkstown.com/story19051665/the-fact-about-bip39-seed-phrase-word-list-that-no-one-is-suggesting