Dictionary.com
Thesaurus.com
Synonyms

unfamiliar

American  
[uhn-fuh-mil-yer] / ˌʌn fəˈmɪl yər /

adjective

  1. not familiar; not acquainted with or conversant about.

    to be unfamiliar with a subject.

  2. different; unaccustomed; unusual; strange.

    an unfamiliar treat.
    Synonyms:
    new, novel, curious
unfamiliar British  
/ ˌʌnfəˈmɪljə, ˌʌnfəˌmɪlɪˈærɪtɪ /

adjective

  1. not known or experienced; strange

  2. not familiar

"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

  • unfamiliarity noun
  • unfamiliarly adverb

Etymology

Origin of unfamiliar

First recorded in 1585–95; un- 1 + familiar

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.

The current system—where A’s are so common that anything less is stigmatized—discourages students from exploring unfamiliar subjects, says Joshua Greene, a Harvard psychology professor and a member of the committee behind the proposal.

From The Wall Street Journal • Apr. 3, 2026

Some are mentally soothed by repeating specific words or phrases, a phenomenon known as echolalia, which can be misinterpreted by someone unfamiliar with the trait as mocking or uncooperative.

From Los Angeles Times • Apr. 1, 2026

He should not be criticised for failing to shine as a false nine against Japan because it is a role he is unfamiliar with.

From BBC • Apr. 1, 2026

Take another look at that unfamiliar form you mentioned.

From MarketWatch • Mar. 27, 2026

Lena’s hut was gone, replaced by an unfamiliar road with trees on all sides; half the trees had decided to put on their fall colors, but the other half stubbornly clung to summer green.

From Anya and the Nightingale by Sofiya Pasternack

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.