For words that have only 3 letters, there's no 4th letter. Such as with the word “incorporate”, there aren't any a lot more letters afterwards and thus must be the word "increase". The word “addict” is inside the BIP39 wordlist however, you would've employed “addi” for “addict”. Using BIP44 with https://web.archive.org/web/20241223212827/http://bip39-phrase.com/