For words that have only three letters, there isn't a 4th letter. Such as with the word “increase”, there aren't any additional letters afterwards and thus must be the word "incorporate". The word “addict” is inside the BIP39 wordlist however, you might have utilized “addi” for “addict”. bip39-phrase.com is definitely https://olivebookmarks.com/story19695918/a-review-of-bip39-phrase-list