For words that only have three letters, there is no 4th letter. For example with the word “include”, there are no far more letters Later on and therefore must be the word "increase". The word “addict” is from the BIP39 wordlist but you might have applied “addi” for “addict”. By https://listbell.com/story9242654/the-ultimate-guide-to-bip39-seed-phrase-github