For words that have only three letters, there is not any 4th letter. For instance with the word “incorporate”, there won't be any extra letters afterwards and therefore have to be the word "insert". The word “addict” is within the BIP39 wordlist however, you would've utilized “addi” for “addict”. A https://reallivesocial.com/story4712269/top-latest-five-bip39-seed-phrase-mnemonics-generator-urban-news