For words that have only three letters, there is absolutely no 4th letter. For example with the word “add”, there isn't any additional letters afterwards and thus should be the word "increase". The word “addict” is in the BIP39 wordlist but you would've made use of “addi” for “addict”. Unlock https://monobookmarks.com/story18938589/examine-this-report-on-bip39-mnemonic-phrase-tool