what does red flag mean

A "red flag" means a warning sign or signal that indicates potential danger, problems, or issues ahead. It can be used literally, such as a red flag warning dangerous conditions, or figuratively to describe behaviors or signs that suggest something may be wrong or risky, especially in relationships or situations. For example, in dating, a red flag may be a warning about someone's behavior that could lead to relationship problems later. Overall, it suggests caution or the need to pay attention to a possible threat or serious concern.