unknown

1 of 2

adjective

un·​known ˌən-ˈnōn How to pronounce unknown (audio)
: not known or not well-known
also : having an unknown value
an unknown quantity

unknown

2 of 2

noun

1
: one that is not known or not well-known
especially : a person who is little known (as to the public)
2
: something that requires discovery, identification, or clarification: such as
a
: a symbol (such as x, y, or z) in a mathematical equation representing an unknown quantity
b
: a specimen (as of bacteria or mixed chemicals) required to be identified as an exercise in appropriate laboratory techniques

Examples of unknown in a Sentence

Adjective a disease of unknown cause Much remains unknown about his early life. Her music was previously unknown outside of Asia. An unknown number of cases go unreported. The victim's attacker was unknown to her. For some unknown reason, my computer crashed. a book of unknown poems Noun explorers venturing off into the unknown A fear of the unknown kept her from changing jobs. The director cast an unknown in the lead role. We're facing too many unknowns.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
But apparently, like Highland when used in reference to the latest Model 3, this isn’t an official Tesla term, and the origin of it is unknown. James Morris, Forbes, 24 Jan. 2025 He was last seen wearing a blue baseball cap with an unknown white logo, a blue long sleeve shirt and baggy jeans. Stepheny Price, Fox News, 23 Jan. 2025
Noun
By Gautam Naik | Bloomberg Among natural disasters, wildfires are the great unknown. Bloomberg, The Mercury News, 22 Jan. 2025 Others, though, questioned whether the potential benefits were worth the risk, particularly given the host of unknowns surrounding Covid-19, and the lack of available treatments at the time. Smithsonian Magazine, 10 Jan. 2025 See all Example Sentences for unknown 

Word History

First Known Use

Adjective

14th century, in the meaning defined above

Noun

1597, in the meaning defined at sense 1

Time Traveler
The first known use of unknown was in the 14th century

Dictionary Entries Near unknown

Cite this Entry

“Unknown.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unknown. Accessed 31 Jan. 2025.

Kids Definition

unknown

1 of 2 adjective
un·​known ˌən-ˈnōn How to pronounce unknown (audio)
: not known
also : having an unknown value
an unknown quantity

unknown

2 of 2 noun
1
: something that is unknown
2
: a symbol (as x, y, or z) representing a quantity whose value is unknown
an equation with two unknowns

More from Merriam-Webster on unknown

Last Updated: - Updated example sentences
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