Irresponsibly is an adjective that can describe actions or behaviors that are reckless, careless, thoughtless, and heedless. There are several synonyms for irresponsibly that can be used interchangeably depending on the context. Recklessly implies a disregard for consequences or rules, while carelessly implies a lack of attention or foresight. Thoughtlessly suggests a lack of consideration for others or the situation at hand, while heedlessly suggests a lack of regard for dangers or risks. Other synonyms for irresponsibly include negligently, rashly, impetuously, and imprudently. It is important to choose the appropriate synonym to accurately convey the intended meaning and tone of your message.