For words that have only 3 letters, there is no 4th letter. For example with the word “increase”, there aren't any a lot more letters Later on and thus have to be the word "increase". The word “addict” is within the BIP39 wordlist however, you would have applied “addi” for https://bookmarkingace.com/story18809242/new-step-by-step-map-for-ledger-seed-phrase-bip39