"Take under one's wing" is a phrase used to describe the act of offering support, guidance, and protection to someone in need. Antonyms of this phrase would mean to neglect or abandon someone who needs help. Some potential antonyms include abandoning, isolating, ignoring, disregarding, or neglecting. These words describe behaviors that are opposite to "taking someone under one's wing" and imply a lack of care, concern, or warmth towards others. It is important to keep in mind that using negative behaviors towards others can have consequences that are not helpful to anyone involved in the situation. Therefore, it is important to treat others with the kindness and care they deserve.