Productivity-boosting, efficient, fruitful, time-saving, purposeful, beneficial, constructive, profitable, goal-oriented, valuable, significant, worthwhile, efficient. All of these terms are antonyms for the term "time-wasting". When people are being productive, they're making progress towards a goal, using their time in a way that is valuable and has a clear benefit. Conversely, when people are wasting time, they're engaging in activities that don't provide any return on investment or further their goals in any way. It's essential to recognize the value of time and spend it wisely. By using time effectively, people can accomplish their goals and feel more fulfilled and successful.