For words that only have 3 letters, there isn't any 4th letter. For instance with the word “increase”, there won't be any much more letters afterwards and therefore should be the word "incorporate". The word “addict” is during the BIP39 wordlist but you would have employed “addi” for “addict”. Meticulously https://getsocialsource.com/story4431309/details-fiction-and-bip39