A person who commits crimes, does bad things, or is generally immoral. I thought I could trust him, but that no-goodnik double-crossed me and made off with the money!The government agency is full of no-goodniks willing to bend the rules for a bribe.
no-goodnik
(noˈgʊdnɪk)
n. someone who is no good. (The nik is from Russian via Yiddish.) Tell the no-goodnik to leave quietly, or I will call the police.