The term "hanging onto" is often used to imply a sense of grasping on tight to something or someone. Its antonyms, therefore, would refer to the opposite of this feeling. For instance, letting go, releasing, and surrendering would all be considered antonyms. Other examples include dropping, abandoning, and relinquishing. Essentially, these words signify an act of freeing oneself from the attachment, whether it be emotional or physical. It's important to note that letting go doesn't mean giving up or losing control, but rather accepting that certain things are beyond our control and it's better to move on.