Used of sleep, meaning sleep with no dreams in it — and by extension, the deep, heavy, restful kind. That extension is the whole point of the word.

Used of sleep這個字用在睡眠上，meaning意思是 sleep with no dreams in it睡眠裡沒有夢；and by extension引申來說，the deep, heavy, restful kind指的是那種深沉、沉重、很能休息的睡眠。That extension is the whole point of the word這個引申義才是這個字的重點所在。

Strictly it only tells you what was absent, but nobody says 'dreamless' to report a fact about dream activity; they say it to mean the sleep went down so deep that nothing surfaced, and you woke feeling like no time had passed. So it is a compliment about rest.

Strictly嚴格來說，it only tells you what was absent這個字本來只是告訴你「沒有作夢」，but nobody says 'dreamless'但沒有人會說『dreamless』 to report a fact about dream activity是為了要報告做夢這件事的事實；they say it他們說這個字 to mean the sleep went down so deep that nothing surfaced是要表示睡得太沉、什麼都沒有浮現，and you woke feeling like no time had passed醒來時感覺時間好像沒有過去。So it is a compliment about rest所以這其實是在稱讚睡得好。

It appears almost only in the phrase 'a dreamless sleep', and it is bookish — you meet it in novels and in careful writing, while in conversation people say 'I slept like a log' or 'I was out cold'.

It appears almost only這個字幾乎只出現 in the phrase 'a dreamless sleep'在『a dreamless sleep』這個說法裡，and it is bookish而且偏書面，you meet it in novels and in careful writing你會在小說和講究的文章裡看到它，while in conversation而在日常對話中，people say 'I slept like a log'大家會說『I slept like a log』（睡得像根木頭），or 'I was out cold'或『I was out cold』（累到昏睡過去）。

One thing worth knowing: in older literature 'dreamless sleep' is sometimes a gentle way of talking about death, so if the surrounding sentence sounds solemn, check which one is meant.

One thing worth knowing有一件事值得知道：in older literature在比較舊的文學作品裡，'dreamless sleep' is sometimes a gentle way of talking about death『dreamless sleep』有時候是委婉說死亡的方式，so if the surrounding sentence sounds solemn所以如果前後文聽起來很嚴肅，check which one is meant就要判斷是指哪一個意思。