For words that only have 3 letters, there isn't any 4th letter. For example with the word “incorporate”, there isn't any extra letters afterwards and so should be the word "add". The word “addict” is in the BIP39 wordlist however you might have utilised “addi” for “addict”. Artwork is actually https://bookmarkextent.com/story20675814/top-latest-five-bip39-words-urban-news