The phrase "copping some z's" is a colloquial expression that is commonly used to refer to getting some sleep or taking a nap. However, some suitable antonyms for this phrase include "staying awake," "remaining alert," or "maintaining wakefulness." These words represent actions that are in opposition to the act of sleeping and suggest a state of being awake and attentive. These antonyms may come in handy when one needs to stay alert and focused, especially when dealing with important tasks that require our full attention. Therefore, while getting enough sleep is essential for maintaining a healthy lifestyle, there are times when being awake is equally important.