For words that only have three letters, there isn't any 4th letter. As an example with the word “include”, there isn't any far more letters Later on and therefore needs to be the word "add". The word “addict” is from the BIP39 wordlist however, you would've employed “addi” for “addict”. https://todaybookmarks.com/story18946074/detailed-notes-on-copyright-wallet-seed-phrase-out-of-bip39