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Synonyms

unsure

American  
[uhn-shoor, ‐shur] / ʌnˈʃʊər, ‐ʃɜr /

adjective

  1. not certain or confident.

    He arrived at the party unsure of his welcome.

  2. unknown or liable to change; not determined or definite.

    The monthly trend for this stock is still unsure, but the daily trend is upward.

    What happened next is unsure.


unsure British  
/ ʌnˈʃʊə /

adjective

  1. lacking assurance or self-confidence

  2. (usually postpositive) without sure knowledge; uncertain

    unsure of her agreement

  3. precarious; insecure

  4. not certain or reliable

"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

Etymology

Origin of unsure

First recorded in 1400–50; Middle English unseur(e) “unsafe; precarious; uncertain”; un- 1 ( def. ) + sure ( def. )

Explanation

If you're unsure, you don't feel confident. It's natural to feel unsure of yourself the very first time you read your poems in front of an audience. When you feel unsure, you find yourself full of doubt. If you remember how unsure you felt on your first day of school, you may want to befriend that new kid who looks unsure about where to sit in class. You can be unsure of yourself, or unsure how to comfort your friend whose cat just died. When this word was originally used in the 15th century, it primarily meant "not safe from attack."

Keep Reading on Vocabulary.com

Vocabulary lists containing unsure

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.

In 1855, Natalie is unsure who’s watching — a cruel producer?

From Los Angeles Times • Apr. 7, 2026

"It's truly very sad to know people had to abandon homes built over a lifetime, unsure if they will ever return."

From Barron's • Apr. 5, 2026

The company lost focus, unsure if it was selling to sneakerheads or soccer moms.

From The Wall Street Journal • Mar. 31, 2026

For years, scientists were unsure where TMEM175 was located in cells or what it actually did.

From Science Daily • Mar. 26, 2026

She opened and closed her mouth a few times, unsure of the best thing to say.

From "The Marvellers" by Dhonielle Clayton