When it comes to synonyms for the phrase "without caution," you have a variety of options to choose from. The first word that comes to mind is "recklessly," which instantly implies a lack of concern for potential consequences. Another option is "carelessly," which suggests a similar disregard for careful consideration or attention to detail. "Thoughtlessly" and "haphazardly" are other choices that capture the idea of acting without regard for potential risks or consequences. Of course, it's important to note that acting without caution can have serious implications, so be sure to consider the context before using any of these synonyms in your writing.