Being on your guard means to be cautious and aware of potential danger or trouble. There are numerous other terms that convey similar meanings such as being alert, vigilant, watchful, wary, cautious, and attentive. These synonyms are useful in conveying different levels of intensity of being on one's guard, from simply being attentive to potential risks, to being actively on the lookout to prevent harm from occurring. Whether in everyday life situations or in high-risk environments, it's important to remain on guard and pay attention to your surroundings in order to stay safe and avoid potential harm.