Finally, exhausted and exhilarated , he soon fell into a mercifully dreamless sleep.是什么意思？

Finally, exhausted and exhilarated , he soon fell into a mercifully dreamless sleep.

最后, 他觉得困乏了,可还是喜孜孜的, 终于很快就昏昏沉沉地睡着了.

finally

adv. 最后，终于，总算，末后，结果；

例句
...until the great day came when the Germans could finally settle accounts with the British...
直到德国人最终能和英国人清算旧账的重大日子的来临

exhausted

adj. 耗尽的，用完的，筋疲力尽的，精疲力竭的；v. 用尽( exhaust的过去式和过去分词 )，使非常疲倦，详尽讨论（或研究），弄空；

例句
She arrived home exhausted and barely capable of showering before collapsing on her bed.
她精疲力竭地回到家，勉强冲了个澡就倒在了床上。

and

conj. 和，与，而且，于是，然后，因此；

例句
I spend a lot on expensive jewelry and clothing...
我花很多钱购买昂贵的首饰和衣服。

exhilarated

v. 使高兴，使兴奋( exhilarate的过去式和过去分词 )；

例句
You must be feeling exhilarated by the call of the new.
新鲜事物的魅力一定让你兴奋不已。

he

pron. 他，它，一个人；n. 雄性动物；

例句
Logic had prevailed and he had abandoned the idea.
最终理智占了上风，他打消了那个念头。

soon

adv. 立刻，马上，一会儿，不久，快，宁愿；

例句
The minister advised him to leave as soon as possible...
部长建议他尽快离开。

fell

vt. 砍倒，打倒；n. 兽皮，一季的木材采伐量；adj. 残忍的，凶恶的；v. 掉下，摔倒，变坏(fall的过去式)；

例句
One afternoon, I grew bored and actually fell asleep for a few minutes...
一天下午，我觉得有些无聊，还真的睡着了一小会儿。

into

prep. （表示方向）进入…中，（表示所属）输入，（表示状态）进入…状态，（表示时间）持续到；

例句
By 1838, the abolitionists had shamed parliament into ending slavery in British colonies...
到1838年，废奴主义者迫使议会出于道德压力而废除了英国殖民地的奴隶制。

mercifully

adv. 幸运地，宽厚地，仁慈地；

例句
The exhibition is informative, up to date, and mercifully free of gimmicks.
这个展览既能让人增长见识，又紧跟时代前沿，而且幸运的是没有华而不实的东西。

dreamless

adj. 无梦的，不做梦的；

例句
He fell into a deep dreamless sleep.
他酣然入睡，一夜无梦。

sleep

vi.& link-v. 睡，睡觉；vi. 睡，睡觉，睡眠状态；vt. 为…提供床位，提供住宿，以睡觉打发日子；n. 睡眠；

例句
Their sleep is regularly disturbed by the sound of gunfire as criminal gangs settle their nightly accounts.
他们经常被黑帮每晚火拼的枪声所吵醒。