Answer: Wastefulness is spending money inefficiently.

It is opposite to stinginess, which means withholding money and not spending it rightfully.

The correct attitude is a moderate way between wastefulness and stinginess, i.e., to be generous.

Allah Almighty says: {And those who neither spend wastefully nor stingily, but are moderate between them.} [Surat al-Furqān: 67]