The phrase "diddled away" suggests wasting time or resources. To find antonyms for this term, one could consider words that convey productivity, efficiency, or focus. For example, antonyms might include "invested," "used wisely," "made progress," "completed tasks," "maximized potential," or "achieved goals." These contrasting terms suggest a more purposeful approach to using one's time, energy, and other resources. Rather than simply squandering these valuable assets, individuals who use antonyms for "diddled away" might make deliberate choices that enhance their effectiveness and enable them to accomplish more in less time.