Antonyms for the word "are startled" are words that describe the opposite feeling or emotion. Instead of feeling startled, a person might feel calm, collected, serene, or composed. Other antonyms include relaxed, composed, cool, sedate, unperturbed, and unflappable. These words describe states of being that are the opposite of the sudden, jarring surprise of being startled. For example, if you see a snake unexpectedly, you might be startled, but if you are in a peaceful forest clearing listening to the birds, you are more likely to feel calm and composed. Antonyms provide a range of emotions and help us better describe our experiences and feelings.