It's foolish to while away one's time in idle talk

把时间花费在闲谈上是很愚蠢的。

　　while away: pass（the time）in a leisurely way 消磨（时间）
　　再如:
　　I was glad of his company to while away an hour until the train came.
　　在等车的一小时中，有他作伴消磨时间，我很高兴。