Unperilous is a word that describes something as not being dangerous or risky. It can be replaced with words such as safe, secure, guarded, harmless, and unthreatening. These words are commonly used to describe situations where there is no potential for harm or danger. For example, a safe journey would imply that the trip is not hazardous. Similarly, a secure location would indicate that the place is free from threats and risks. Overall, the synonyms for unperilous reflect a sense of safety and security, giving a peaceful and reassuring feeling to readers and listeners.