For words that only have three letters, there is absolutely no 4th letter. For instance with the word “incorporate”, there are no more letters afterwards and thus should be the word "increase". The word “addict” is inside the BIP39 wordlist but you would've utilized “addi” for “addict”. A number of https://myfirstbookmark.com/story18829097/how-much-you-need-to-expect-you-ll-pay-for-a-good-valid-bip39-seed-phrase