The phrase 'bit one's nails' is often used to describe a nervous or anxious person. However, there are many antonyms for this phrase that describe the opposite emotions. For example, a person who is confident and self-assured might feel 'calm' or 'relaxed.' Instead of biting their nails, they might find a way to release their tension, such as deep breathing or meditation. A person who is happy and content might feel 'joyful' or 'excited.' Instead of biting their nails, they might express their happiness through laughter or conversation with friends. Whatever the antonym, it's important to find healthy ways to deal with our emotions in order to live a balanced and fulfilling life.