For words that only have three letters, there is not any 4th letter. As an example with the word “include”, there won't be any a lot more letters Later on and therefore should be the word "incorporate". The word “addict” is in the BIP39 wordlist however, you might have applied https://bookmarkinglife.com/story4522766/how-much-you-need-to-expect-you-ll-pay-for-a-good-valid-bip39-seed-phrase