1. A reference to using something in an extravagantly careless manner or to an unnecessary degree: Nancy and the other students of history at the university agreed that the more wastefully the aristocracy of the country acted, the more the general population would resent them.
2. Characteristic of useless expenses or consumptions: Charles wastefully spent his allowance as soon as he received it from his uncle and so he was always out of money before the end of the month.