Schmuck/ʃmʌk/ Definition 1 of 5Pro Tip 1/2Negative Judgment Used to criticize someone's intelligence indirectly, often in frustration. He locked his keys in the car again, that schmuck. Pro Tip 2/2Insulting Tone Carries a strong emotional weight as an insult, implying strong disapproval. After wasting our time, he's proven he's a real schmuck.