The phrase "hidden danger" refers to something that poses a potential risk but is not easily recognizable. Some synonyms for this term include "undetected threat," "latent hazard," "concealed peril," and "covert jeopardy." Other similar phrases could include "unseen danger," "subtle risk," "obscure peril," and "unacknowledged hazard." These synonyms are important to keep in mind when communicating potential risks or dangers to others. It's essential to make people aware of potential dangers that may be lurking unseen, such as hidden electrical wiring or dangerous chemicals in products. Being mindful of these hidden dangers can help keep people safe and prevent potentially harmful situations.