Twist the knife is a phrase that means to intensify someone's pain or suffering. It's a metaphorical expression that's often used in connection with causing emotional, mental, or psychological distress. When you twist the knife, you make a bad situation worse by adding more pain to an already painful situation. Some possible synonyms for twist the knife include rub salt in the wound, exacerbate, aggravate, make matters worse, and pour oil on the fire. Each of these terms implies making someone's suffering or problems even more challenging, often to the point of causing further damage or injury. Regardless of the specific words used, all of these expressions speak to the same core idea of making things worse, not better.