When someone is "over bold," it means they are too daring or reckless. Antonyms for "over bold" might include words like cautious, reserved, timid, or hesitant. These words describe a person who is more careful and thoughtful in their actions, rather than someone who rushes into things without considering the consequences. Being cautious or hesitant can be advantageous in certain situations, as it allows one to weigh the risks and benefits of a decision before acting. So while being "over bold" may seem brave, it can also be detrimental to one's safety and well-being.