If something is unknown to you, you have no knowledge of it.
An unknown number of demonstrators were arrested.
不知多少示威者被逮捕了。
The motive for the killing is unknown.
杀人动机不明。
An unknown person is someone whose name you do not know or whose character you do not know anything about.
the tomb of the unknown soldier.
那位无名士兵的墓。
An unknown person is not famous or publicly recognized.
He was an unknown writer.
他是个没有名气的作家。
If you say that a particular problem or situation is unknown, you mean that it never occurs.
A hundred years ago coronary heart disease was virtually unknown in America.
100年前,冠心病在美国几乎从未出现过。
unknowns
An unknown is something that is unknown.
The length of the war is one of the biggest unknowns.
战争会持续多久是最大的未知数之一。
An unknown is a person who is unknown.
Within a short space of time a group of complete unknowns had established a wholly original form of humour.
在短短的一段时间内,一群完全不为人知的人始创了一种新式幽默。
The unknown refers generally to things or places that people do not know about or understand.
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。