For words that only have 3 letters, there's no 4th letter. Such as with the word “increase”, there won't be any far more letters afterwards and therefore should be the word "add". The word “addict” is during the BIP39 wordlist however , you might have utilised “addi” for “addict”. bip39-phrase.com https://ok-social.com/story4472445/phrases-with-bit-an-overview