Antonyms for the word "wellwishers" include ill-wishers, antagonists, detractors, foes, enemies, and naysayers. These are individuals who hold negative opinions or feelings towards a person or organization, wishing them to fail or suffer. They may actively work to undermine the success and well-being of others, rather than offer support and encouragement. Ill-wishers may view others as rivals or threats, and seek to elevate themselves by bringing others down. It is important to be aware of ill-wishers and their negative energy, but it is equally important to focus on the positive energy and support provided by wellwishers.