For words that have only 3 letters, there is no 4th letter. Such as with the word “increase”, there won't be any a lot more letters Later on and thus should be the word "incorporate". The word “addict” is inside the BIP39 wordlist however , you would have applied “addi” https://socialrator.com/story9408184/the-ultimate-guide-to-bip39-seed-phrase-github