The phrase "bites one's nails" refers to someone who is nervous, anxious, or stressed. The antonyms, on the other hand, would be words that reflect the opposite emotions. These might include words like calm, relaxed, composed, or peaceful. When someone is calm, they are composed and in control of their emotions, while a relaxed person is at ease and free from worry. Feeling peaceful also implies a sense of tranquility and serenity. By cultivating these opposite emotions, it's possible to reduce the behavior of biting one's nails and manage stress more effectively. So, to avoid biting one's nails, try practicing mindfulness, meditation or relaxation techniques.