For words that have only 3 letters, there is not any 4th letter. As an example with the word “increase”, there aren't any far more letters Later on and thus have to be the word "incorporate". The word “addict” is in the BIP39 wordlist however you would've utilised “addi” for https://thegreatbookmark.com/story19186034/how-much-you-need-to-expect-you-ll-pay-for-a-good-bip39-seed-phrase-mnemonics-generator