A sense of security is a feeling of safety and protection that brings comfort and peace of mind. There are several words and phrases that can be used as synonyms to describe this feeling including safety, confidence, comfort, assuredness, reassurance, peace, and stability. Other expressions that convey the same idea are a feeling of being sheltered, a sense of wellbeing, a sense of belonging, and a sense of calmness. Whether it's a sense of security in one's home, job, or personal relationships, having that feeling is important for one's mental and emotional wellbeing.