For words that have only three letters, there is not any 4th letter. Such as with the word “include”, there aren't any additional letters afterwards and thus have to be the word "increase". The word “addict” is during the BIP39 wordlist however, you might have employed “addi” for “addict”. The https://onelifesocial.com/story4337017/facts-about-bip39-seed-phrase-word-list-revealed