For words that only have 3 letters, there is not any 4th letter. One example is with the word “incorporate”, there are no far more letters Later on and therefore have to be the word "insert". The word “addict” is during the BIP39 wordlist but you would've applied “addi” for https://sociallytraffic.com/story3740744/the-definitive-guide-to-bip39-seed-phrase