Antonym: known. Similar words: flunk, skunk, chunk, trunk, know, sunken, debunk, knob. Meaning: [ʌnˈnəʊn] 
n. 1. an unknown and unexplored region 2. anyone who does not belong in the environment in which they are found 3. a variable whose values are solutions of an equation. adj. 1. not known 2. being or having an unknown or unnamed source 3. not known to exist 4. not famous or acclaimed 5. not known before.
n. 1. an unknown and unexplored region 2. anyone who does not belong in the environment in which they are found 3. a variable whose values are solutions of an equation. adj. 1. not known 2. being or having an unknown or unnamed source 3. not known to exist 4. not famous or acclaimed 5. not known before. 
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1. Wade not in unknown water.
2. No safe wading in an unknown water. 
3. The outcome of their discussion is still unknown.
4. A generation ago genetic codes were certainly unknown.
5. Life is like a journey with an unknown destination.
6. The cause of autism is unknown.
7. The origins of the custom are unknown.
8. The present whereabouts of the manuscript is unknown.
9. They bowed in homage to the Unknown Soldiers.
10. The murderer's identity remains unknown .
11. The identity of the killer is still unknown.
12. The fate of the three men is unknown.
13. It was unknown country to me.
14. An unknown number of demonstrators were arrested.
15. You must eliminate an unknown quantity.
16. These sites remain largely unknown to the British public.
17. An unknown man has stolen all her money.
18. The man's identity remains unknown.
19. Love is an unknown place that no saying from all around the worldcan explain.
20. The best thing to do when entering unknown territory is smile.
20. Sentencedict.com try its best to gather and create good sentences.
21. Someone unknown tipped off the police about the plan to rob the bank.
22. I'm working toward the slice of the unknown future step away(sentencedict.com), never stop.
23. The very concept of free speech is unknown to them.
24. I have finished my role play, now need unknown life. I want to go back home, the village in childhood frolicking hillside walk.
25. Those who dared to launch out beyond the unknown waters became the discoverers of new lands.
26. The doctors have attributed the cause of the illness to an unknown virus.
27. Miracle, is not on the way to easy to bloom.Perhaps, in all, there is no behind trying to choose, there will be not seen, not design the unknown.
28. What the weather will be like on the day is, as always, the great unknown.
29. The arrival of a taxi was unusual enough; an unknown woman getting out of it was sensational.
30. The exact number of people carrying the virus is unknown.
More similar words: flunk, skunk, chunk, trunk, know, sunken, debunk, knob, drunken, knock, junk mail, hunker down, know about, knock out, knock off, well-known, well known, knock down, knowledge, doorknob, hunkered down, acknowledge, acknowledgement.