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wasteful; a waste
too good; more than one deserves; unworthy of
impious; profane; sacrilegious
食べ物を捨てるのはもったいない。
It is wasteful to throw away food.
あの才能を活かさないのはもったいなかった。
It was a waste not to make use of that talent.
値段を考えればこの品質はもったいなくない。
Considering the price, this quality isn't a waste.