For words that have only 3 letters, there's no 4th letter. Such as with the word “add”, there isn't any extra letters Later on and therefore has to be the word "incorporate". The word “addict” is within the BIP39 wordlist however you would have applied “addi” for “addict”. Artwork is https://guidemysocial.com/story4428624/helping-the-others-realize-the-advantages-of-bip39-seed-phrase-mnemonics-generator