The phrase "under one wing" typically refers to someone or something being under the protection or guidance of someone else. Antonyms for this phrase may include "independent," "self-reliant," "autonomous," or "self-sufficient." These words describe a state of being where one is not dependent on someone else for their well-being, and can take care of themselves without assistance. Other antonyms could include "unprotected," "unsupported," or "neglected," implying a lack of care or concern for someone or something. The opposite of 'under one wing', therefore, represents a sense of freedom, control, or responsibility, where one is able to make their own choices and pursue their own ambitions independently.