Expending, or tending to expend, property, or that which is valuable, in a needless or useless manner; lavish; prodigal; as, a wasteful person; a wasteful disposition
Action that is wasteful uses too much of something valuable such as time, money, or energy. This kind of training is ineffective, and wasteful of scarce resources Try to avoid wasteful duplication of effort. using more of something than you should, especially money, time, or effort
inefficient in use of time and effort and materials; "a clumsy and wasteful process"; "wasteful duplication of effort"; "uneconomical ebb and flow of power"