The antonyms for the word "more overanxious" can include "complacent," "carefree," "relaxed," "calm," "cool-headed," and "unworried." When someone is overanxious, they tend to become excessively worried, nervous, and stressed about minor things. However, if that person is complace, they are content with their current situation and don't feel the need to worry or stress about anything. Carefree individuals tend to live in the moment and not worry about the future. Meanwhile, relaxed and calm people don't get worked up easily and keep a level head in stressful situations. Unworried individuals don't let anxiety or stress affect their day-to-day life.