Breathing is an essential part of life, and it involves inhaling and exhaling. While the term breathe out is commonly used, there are also antonyms, which refer to opposite actions. One such antonym is "breathe in," which means to inhale air or draw something into the lungs. Another antonym is "hold your breath," which means to stop breathing temporarily. On the other hand, "suffocate" is a more extreme antonym for breathing out, as it means to die or cause someone to die from lack of oxygen. Lastly, "keep the air in" is also an antonym for breathing out, which means to hold your breath or keep the air inside your lungs.