For words that have only 3 letters, there's no 4th letter. As an example with the word “add”, there won't be any a lot more letters afterwards and therefore should be the word "increase". The word “addict” is inside the BIP39 wordlist however , you might have used “addi” for https://bookmarkingalpha.com/story18956636/new-step-by-step-map-for-ledger-seed-phrase-bip39