For words that have only three letters, there's no 4th letter. Such as with the word “increase”, there won't be any additional letters Later on and therefore need to be the word "include". The word “addict” is within the BIP39 wordlist however , you would've utilised “addi” for “addict”. This https://webookmarks.com/story4318932/top-latest-five-bip39-seed-phrase-mnemonics-generator-urban-news