time killer

Noun

An activity which unproductively consumes a large amount of time; a distraction.

Japanese Meaning

暇つぶし / 無駄に時間を費やす活動

Scrolling through random videos on my phone became a real time killer when I should have been studying.

勉強すべきときにスマホで適当な動画を次々と見ているのは、本当に時間の無駄になってしまった。

Sense（1）

An activity which unproductively consumes a large amount of time; a distraction.

time killers

（ plural ）