For words that only have 3 letters, there is no 4th letter. Such as with the word “incorporate”, there aren't any more letters afterwards and therefore need to be the word "include". The word “addict” is from the BIP39 wordlist but you would have used “addi” for “addict”. Various Wallets:For https://mysitesname.com/story8548580/5-simple-techniques-for-bip39-seed-phrase