Dictionary.com
Thesaurus.com
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.

Union representatives say mixed messaging has left employees unsure whether they can rely on upcoming paychecks.

From Barron's • Apr. 10, 2026

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

From The Wall Street Journal • Mar. 31, 2026

In the absence of clear communication, and amid an ongoing internet blackout, many described feeling exposed and uncertain, unsure when or where the next strike might hit.

From BBC • Mar. 27, 2026

Scientists were unsure whether those dips were caused by dark spots on the star or by material orbiting nearby.

From Science Daily • Mar. 27, 2026

Pong cut his motor and stared, unsure what to do.

From "A Wish in the Dark" by Christina Soontornvat