The word "over-bold" implies excessive confidence or daring. Some antonyms for this word could be "timid," "cautious," "reserved," "modest," "shy," "reticent," or "self-effacing." These words indicate a lack of confidence, an inclination to be careful rather than taking unnecessary risks, and a preference for humility rather than seeking attention or recognition for one's actions. Being too bold can sometimes lead to negative consequences, making it important to find the right balance between being assertive and being reckless. Using these antonyms can help us express ourselves in a more nuanced way and avoid any misunderstandings or miscommunications.