Dictionary.com
Thesaurus.com
Synonyms

unknowable

American  
[uhn-noh-uh-buhl] / ʌnˈnoʊ ə bəl /

adjective

  1. not knowable; incapable of being known or understood.

noun

  1. something that is unknowable.

  2. the Unknowable, the postulated reality lying behind all phenomena but not cognizable by any of the processes by which the mind cognizes phenomenal objects.

unknowable 1 British  
/ ʌnˈnəʊəbəl /

adjective

  1. incapable of being known or understood

    1. beyond human understanding

    2. ( as noun )

      the unknowable
"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Unknowable 2 British  
/ ʌnˈnəʊəbəl /

noun

  1. philosophy the ultimate reality that underlies all phenomena but cannot be known

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • unknowableness noun
  • unknowably adverb

Etymology

Origin of unknowable

Middle English word dating back to 1325–75; un- 1, knowable

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

And that in turn is conditional on a host of at this stage unknowable developments: the deployment of ground forces, the contribution of neighbors and others to the shipping challenge.

From The Wall Street Journal • Mar. 30, 2026

As he explains to Felix Salmon, Elizabeth Spiers, and Emily Peck, A.I. is a hyperobject that touches everything in unknowable ways.

From Slate • Mar. 14, 2026

The writing is terrifically funny and also grounded, anecdotes filled with slapstick but no punchlines, befitting a story that includes hookups, weddings, children, a funeral and an unknowable future.

From Los Angeles Times • Feb. 2, 2026

The river, at times hauntingly beautiful and others murky and unknowable, offers a mirror to Daniel's torment, and to the increasingly fragile hope of his wife, Agnieszka, that Chris will one day come home.

From Barron's • Jan. 24, 2026

He understood in that moment that he was smaller than he had ever known, and the realm of the unknowable was bigger.

From "Strange the Dreamer" by Laini Taylor

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.