wasteful waste‧ful [ˈweɪstfl] adjective
using things such as money, materials or energy in a way that is not sensible or effective:

• Local government is seen as slow, wasteful, and incompetent.

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wasteful UK US /ˈweɪstfəl/ adjective
not being careful about the amount of resources used for something: »

Top business advisers have been brought in to identify areas of wasteful government spending.

Financial and business terms. 2012.