For words that have only three letters, there is not any 4th letter. For example with the word “increase”, there aren't any much more letters Later on and therefore have to be the word "incorporate". The word “addict” is within the BIP39 wordlist however you would have utilized “addi” for https://single-bookmark.com/story19078812/the-fact-about-valid-bip39-seed-phrase-that-no-one-is-suggesting