Which synonym can be associated with 'perilous'?

The term 'perilous' inherently describes a situation or condition that is fraught with danger or risk. It is often used to convey a sense of immediate threat or significant hazard. Therefore, the synonym that aligns closely with this meaning is 'dangerous.' This word captures the essence of being at risk or likely to cause harm, which is the core implication of 'perilous.'

In contrast, 'safe' suggests a lack of risk or danger, 'harmless' implies no potential for harm, and 'cautious' relates more to being careful or avoiding risk rather than describing a state of danger itself. Understanding these nuances in meaning helps to reaffirm why 'dangerous' is the most appropriate synonym.