"Going headlong" means to do something impulsively without considering the outcomes. There are several synonyms for this phrase, including recklessly, rashly, hastily, impetuously, and thoughtlessly. Each of these words describes a behavior that is frenzied and reckless. People who act recklessly or rashly do not think before they make decisions, which can lead to negative outcomes. Those who act hastily or impetuously tend to be impatient and make snap judgments, often without all of the information available. Overall, using these synonyms can help to provide a broader understanding of the mindset behind "going headlong" and ultimately encourage more thoughtful, calculated decision-making.