For words that only have 3 letters, there is not any 4th letter. One example is with the word “incorporate”, there isn't any extra letters afterwards and therefore have to be the word "include". The word “addict” is within the BIP39 wordlist however , you might have made use of https://iowa-bookmarks.com/story14580246/top-latest-five-bip39-seed-phrase-mnemonics-generator-urban-news