When we talk about whiling away hours, we usually mean spending time in a leisurely, relaxed way. However, there are plenty of antonyms for this phrase that convey a much different feeling. Instead of wasting time, you could be using it productively. Instead of daydreaming, you could be focused and productive. You might be working hard, learning new skills, or completing tasks that bring you closer to your goals. Essentially, any activity that involves actively engaging your mind and body, rather than simply passing the time, would be considered an antonym of whiling away hours. So whether you're studying, exercising, or pursuing a passion project, you're making the most of your time instead of simply wasting it.