For words that have only 3 letters, there isn't a 4th letter. Such as with the word “incorporate”, there won't be any far more letters Later on and therefore must be the word "insert". The word “addict” is while in the BIP39 wordlist but you might have made use of https://nybookmark.com/story20391671/a-secret-weapon-for-bip39-words-to-numbers