For words that only have three letters, there's no 4th letter. For instance with the word “increase”, there aren't any more letters afterwards and thus need to be the word "include". The word “addict” is in the BIP39 wordlist however you might have employed “addi” for “addict”. A seed phrase, https://privatebin.net/?57c491b9cad17a10#2jP1wyi3VUgs8q9BTwvowdFnmCxc6BsRV7dxomBiXrt6