someone who causes another person to waste time doing something that does not achieve any good result

The ad was answered by a lot of time-wasters who didn't even seriously want the job. 回复广告的人中有许多人是在浪费别人时间，根本不是真想要这份工作。

an activity that takes a lot of time and does not achieve anything important

The internet has replaced television as the biggest time-waster ever invented. 互联网已取代电视成了有史以来人类发明的最能用来浪费时间的活动。