For words that have only three letters, there isn't a 4th letter. For example with the word “increase”, there isn't any a lot more letters Later on and thus must be the word "incorporate". The word “addict” is within the BIP39 wordlist but you might have applied “addi” for “addict”. https://loanbookmark.com/story18906254/examine-this-report-on-bip39-mnemonic-phrase-tool