For words that only have 3 letters, there is not any 4th letter. Such as with the word “include”, there are no more letters Later on and therefore has to be the word "include". The word “addict” is within the BIP39 wordlist but you would've employed “addi” for “addict”. Should https://thegreatbookmark.com/story19510214/little-known-facts-about-bip39-seed-phrase-list