For words that only have 3 letters, there's no 4th letter. By way of example with the word “increase”, there aren't any additional letters afterwards and thus must be the word "incorporate". The word “addict” is inside the BIP39 wordlist however, you would've applied “addi” for “addict”. Artwork is a https://bookmarkleader.com/story18976307/the-ultimate-guide-to-bip39-seed-phrase-mnemonics-generator