For words that only have 3 letters, there's no 4th letter. For example with the word “insert”, there won't be any far more letters Later on and therefore must be the word "increase". The word “addict” is while in the BIP39 wordlist however you might have utilised “addi” for “addict”. https://nowbookmarks.com/story19176339/new-step-by-step-map-for-ledger-seed-phrase-bip39