For words that only have 3 letters, there isn't any 4th letter. For instance with the word “incorporate”, there aren't any extra letters Later on and therefore has to be the word "include". The word “addict” is in the BIP39 wordlist however , you would've utilised “addi” for “addict”. Using https://sites2000.com/story8681912/helping-the-others-realize-the-advantages-of-bip39-seed-phrase-mnemonics-generator