For words that have only 3 letters, there is no 4th letter. One example is with the word “include”, there are no much more letters Later on and therefore should be the word "include". The word “addict” is from the BIP39 wordlist but you might have applied “addi” for “addict”. https://greatbookmarking.com/story19640001/a-review-of-bip39-phrase-list