For words that have only three letters, there is no 4th letter. For instance with the word “increase”, there won't be any a lot more letters Later on and therefore should be the word "add". The word “addict” is within the BIP39 wordlist but you might have used “addi” for https://7prbookmarks.com/story18875732/the-ultimate-guide-to-bip39-seed-phrase-github