For words that have only three letters, there isn't a 4th letter. One example is with the word “include”, there isn't any a lot more letters Later on and therefore should be the word "increase". The word “addict” is inside the BIP39 wordlist however , you would have used “addi” https://directmysocial.com/story3617399/how-much-you-need-to-expect-you-ll-pay-for-a-good-valid-bip39-seed-phrase