unknown

adj.

1. 未知的；不详的；未被确认的
   not known or identified
   1. a species of insect previously unknown to science
      科学上以前尚未了解的一种昆虫
   2. He was trying, for some unknown reason , to count the stars.
      不知何故，他试图数星星。
   3. The man's identity remains unknown.
      这名男子的身份还是个谜。
2. 不出名的；无名的
   not famous or well known
   1. an unknown actor
      没有名气的演员
   2. The author is virtually unknown outside Poland.
      在波兰以外，这位作者实际上鲜为人知。
3. 从未发生的；从不存在的
   never happening or existing
   1. The disease is as yet unknown in Europe (= there have been no cases there) .
      这种疾病至今尚未在欧洲出现过。
   2. It was not unknown for people to have to wait several hours (= it happened sometimes) .
      人们得等几个小时的事时有发生。

noun

1. 未知的地方（或事物）
   places or things that are not known about
   1. a journey into the unknown
      探险之旅
   2. a fear of the unknown
      对未知事物的恐惧
2. 无名者；不出名的人
   a person who is not well known
   1. A young unknown played the leading role.
      演主角的是一个名不见经传的年轻人。
3. 不明的情况；未知的因素
   a fact or an influence that is not known
   1. There are so many unknowns in the proposal.
      这项提案中的未知数太多了。
4. 未知数；未知量
   a quantity that does not have a known value
   1. X and Y in the equation are both unknowns.
      等式中的X和Y都是未知数。

1. ADJ 不知道的；不了解的；未知的
   If something is unknown to you, you have no knowledge of it.
   1. An unknown number of demonstrators were arrested...
      有数目不详的示威者遭到了逮捕。
   2. How did you expect us to proceed on such a perilous expedition, through unknown terrain...
      你怎么能指望我们如此冒险地穿越未知的地域，继续这一探险？
   3. The motive for the killing is unknown.
      杀人动机不明。
   4. An unknown is something that is unknown.
      未知的事物
   5. The length of the war is one of the biggest unknowns.
      战争要持续多久是最大的未知数之一。
2. ADJ 不认识的；不熟悉的；陌生的
   An unknown person is someone whose name you do not know or whose character you do not know anything about.
   1. Unknown thieves had forced their way into the apartment...
      不知名的窃贼破门闯入了公寓。
   2. I could not understand how someone with so many awards could be unknown to me.
      我想不通自己竟然不认识获了这么多奖的人。
3. ADJ-GRADED 不出名的；无人知晓的；未获公众认可的
   An unknown person is not famous or publicly recognized.
   1. He was an unknown writer.
      他是个名不见经传的作家。
   2. ...a popular environment where both established and unknown artists can meet, talk and drink.
      成名和未成名的艺术家都可以聚会、聊天及喝酒的一处热门场所
   3. An unknown is a person who is unknown.
      不出名的人
   4. Within a short space of time a group of complete unknowns had established a wholly original form of humour.
      在很短的一段时间内，一群完全籍籍无名之辈创立了一种全新的幽默形式。
4. ADJ 从未发生的；从未存在的
   If you say that a particular problem or situation is unknown, you mean that it never occurs.
   1. A hundred years ago coronary heart disease was virtually unknown in Europe and America.
      在100年前冠心病几乎不存在于欧洲和美洲。
5. N-SING （总称）未知事物，不为人知的地方
   The unknown refers generally to things or places that people do not know about or understand.
   1. Ignorance of people brings fear, fear of the unknown.
      人们的无知会带来恐惧，对未知事物的恐惧。

1. It is not unknown for valuable display items to go, ahem, missing.
   贵重的展品，呃哼，丢失的话，会众人皆知。
2. A previously unknown extremist group has said it carried out Friday's bomb attack.
   一个先前不为人知的极端组织声称实施了星期五的炸弹袭击。
3. My husband, for some unknown reason, suggested that I loved my birds more than him: as if I would
   我丈夫，莫名其妙地，暗示我爱鸟甚于爱他：仿佛我真如此似的。
4. Exactly which bacteria cause the infection is still unknown.
   到底是什么细菌引起的感染还不清楚。
5. Once more he's making a leap into the unknown without a plan.
   他再次毫无计划地乱闯。
6. The letter had come from an unknown mischief-maker.
   这封信来自一个匿名的离间者。
7. The timing of the attack, and its motivations, are unknown.
   袭击发生的时间及其动机尚不清楚。
8. The condition is practically unknown outside psychiatry clinics.
   除了医院的精神病科外，这种病几乎不为人知。
9. The contract was awarded to a previously unknown company
   合同签给了一个之前并不知名的公司。
10. He is an unknown quantity for his rivals.
    对于对手们而言，他是个未知数。
11. Unknown attackers riddled two homes with gunfire
    来路不明的袭击者用枪炮将两处住宅打得千疮百孔。
12. An unknown number of demonstrators were arrested
    有数目不详的示威者遭到了逮捕。
13. How did you expect us to proceed on such a perilous expedition, through unknown terrain
    你怎么能指望我们如此冒险地穿越未知的地域，继续这一探险？
14. The motive for the killing is unknown.
    杀人动机不明。
15. Unknown thieves had forced their way into the apartment
    不知名的窃贼破门闯入了公寓。
16. I could not understand how someone with so many awards could be unknown to me.
    我想不通自己竟然不认识获了这么多奖的人。
17. He was an unknown writer.
    他是个名不见经传的作家。
18. A hundred years ago coronary heart disease was virtually unknown in Europe and America.
    在100年前冠心病几乎不存在于欧洲和美洲。
19. Ignorance of people brings fear, fear of the unknown.
    人们的无知会带来恐惧，对未知事物的恐惧。
20. His present whereabouts is unknown.; His whereabouts is uncertain.
    他目前下落不明。
21. The date of birth and death of Qu Yuan is unknown.
    屈原的生卒年月不详。
22. His present whereabouts is unknown.
    他去处不明。
23. There towers aloft in the square the Monument of Unknown Heroes.
    广场上矗立着无名英雄纪念碑。
24. The address is unknown to me.
    地址未详。
25. His whereabouts have been utterly unknown so far.
    迄今他的下落全然未知。
26. The details of the case is unknown.
    案情未详。
27. This truck is of unknown origin.
    这辆卡车来历不明。
28. The whereabouts of the missing child is still unknown.
    遗失的孩子还没有着落。
29. The whereabouts of this man is unknown.
    这个人去向不明。
30. You must eliminate an unknown quantity.
    你必须消去一个未知数。

adj.

an unknown quantity

• 未知数（指尚不清楚，有待证实的人或事物）
  a person or thing whose qualities or abilities are not yet known

unknown to sb

• …尚不知道；把…蒙在鼓里
  without the person mentioned being aware of it
  1. Unknown to me, he had already signed the agreement.
     他背着我已签了协议。

noun

1. a variable whose values are solutions of an equation

   Synonym:    unknown quantity

2. an unknown and unexplored region
   1. they came like angels out the unknown

   Synonym:    unknown regionterra incognita

3. anyone who does not belong in the environment in which they are found

   Synonym:    strangeralien

adj

1. being or having an unknown or unnamed source
   1. a poem by an unknown author
   2. corporations responsible to nameless owners
   3. an unnamed donor

   Synonym:    namelessunidentifiedunnamed

2. not known before
   1. used many strange words
   2. saw many strange faces in the crowd
   3. don't let anyone unknown into the house

   Synonym:    strange

3. not famous or acclaimed
   1. an obscure family
   2. unsung heroes of the war

   Synonym:    obscureunsung

4. not known
   1. an unknown amount
   2. an unknown island
   3. an unknown writer
   4. an unknown source

5. not known to exist
   1. things obscurely felt surged up from unknown depths