When it comes to antonyms for the phrase "tensing up," several words come to mind, including relaxing, unwinding, loosening, soothing, and calming. Unlike tensing up, which often leads to physical discomfort and emotional turmoil, these words imply a sense of peacefulness and tranquility. Relaxing, for instance, connotes a feeling of restfulness and calmness, whereas unwinding suggests a sense of letting go of stress and anxiety. Loosening implies a release of tension and a more open and flexible state of being, while soothing and calming both suggest a sense of ease and comfort that can help reduce stress, ease tension, and promote overall well-being.