For words that only have three letters, there isn't any 4th letter. One example is with the word “incorporate”, there won't be any far more letters Later on and therefore needs to be the word "increase". The word “addict” is in the BIP39 wordlist however , you would've utilised “addi” https://bookmarkinglive.com/story19638830/bip39-phrase-generator-can-be-fun-for-anyone