A timesuck is an activity that eats up far more of your time than it deserves, usually without giving you much back. It is very informal — internet slang, really — and it is written both as one word and as two (time suck). People use it about the small things that swallow an afternoon: scrolling on your phone, a game you meant to play for ten minutes, a video site that keeps autoplaying. It is not the same as 'a waste of time'. A waste of time is worthless from the start; a timesuck may even be enjoyable, and that is exactly the problem — it pulls you in and you do not notice the hours going. You can say a thing IS a timesuck ('That app is a total timesuck'), and people often add 'total', 'huge', or 'massive' in front of it. It is a noun only; there is no verb 'to timesuck'. Because it is slang, keep it for talking with friends, chat messages, and casual writing — not for a report, an essay, or an email to a teacher. It sounds a little jokey and a little guilty, which is usually why people reach for it: they are admitting to something rather than complaining about it. 'Timesink' means the same thing and is the older word; 'timesuck' is the newer, more casual one, and slightly stronger.

浪費時間的東西、超吸時間的活動（口語，常說「很殺時間」「時間黑洞」）。注意：中文的「殺時間」偏中性，甚至是刻意打發時間；timesuck 帶一點懊惱的意味——你本來沒打算花那麼久。