Over-fastidious is a term that describes someone who is excessively perfectionistic or overly meticulous. Its antonyms, on the other hand, refer to individuals who exhibit less stringent and demanding behavior. The following are some antonyms for over-fastidious: nonchalant, easy-going, laissez-faire, undemanding, relaxed, casual, informal, carefree, and care less. A nonchalant person does not worry too much about details, while an easy-going person is relaxed and unworried. A laissez-faire person is hands-off and does not interfere too much in others' affairs. An undemanding person has simple expectations and is not hard to please. Similarly, relaxed, casual, and carefree individuals are not overly concerned about perfection and strive for comfortable living instead.