Antonyms for the phrase "took the plunge" could include "hesitated," "procrastinated," or "disengaged." Instead of jumping into a decision or action, one could weigh their options, delay the decision, or choose not to act at all. Other antonyms could include "withdrew" or "retreated," indicating a change in course away from the proposed action. While taking the plunge can often mean embracing change or risk, its antonyms suggest a sense of caution, doubt, or even fear. Ultimately, the decision to take the plunge or not depends on the situation, individual, and potential consequences of both actions.