Vocapedia
Log inTry for Free

Looking up...

Explore

  • Words of the Year
  • Recent Lookups
  • Community Collections
  • How to Say

Dictionaries

  • English
  • Vietnamese
  • Japanese
  • Chinese
  • Spanish
  • French
  • Korean
  • German
  • Hindi
  • Italian

MY LEARNING

  • My Dictionary
  • My Collections
  • Reviews

Resources

  • Learning Resources
  • How It Works
  • Study Guides
  • Language Tips
  • FAQ
  • Getting Started
  • For Individuals
  • For Teachers

Community

  • Forum
  • Blog
  • Help Center
  • Partnerships

About

  • About Vocapedia
  • Contact Us
  • Feedback

Legal

  • Terms of Use
  • Privacy Policy
  • Cookie Policy
  • Accessibility
  • GDPR Compliance
© 2026 Vocapedia. All rights reserved.
  1. ホーム /
  2. 辞書 /
  3. English Dictionary /
  4. unsure

unsure

/ʌnˈʃʊər/
uncertain

She was unsure about the decision.

She lacked confidence in making the choice.


neutral

not certain or confident about something

I'm unsure if I should go to the party tonight.

I lack confidence about whether I should attend the party.

He seemed unsure of his own abilities.

He appeared uncertain about his skills.

Used to express hesitation or lack of conviction. Often followed by 'about' or 'of'.

Collocations

unsure aboutlacking confidence in a specific topic or decisionunsure of oneselflacking self-confidence

Synonyms

uncertaindoubtfulhesitantindecisiveambivalent

Antonyms

surecertainconfidentdecisive

Pro Tip

Collocation Tip

Use 'unsure about' for topics (e.g., 'unsure about the rules') and 'unsure of' for abilities or oneself (e.g., 'unsure of herself').

Gold Rule

Grammar Rule

Follow 'unsure' with 'about' + noun phrase or 'of' + noun/pronoun. Avoid using it with 'if' clauses directly (use 'unsure whether' instead).

Word Origin

From Middle English 'unsiker', from Old English 'unsēcere' (not safe), equivalent to 'un-' (not) + 'sure' (from Old French 'seur', from Latin 'securus' meaning 'secure').

Usage Notes

Commonly used in both spoken and written English to express uncertainty. The phrase 'unsure about' is more frequent than 'unsure of' in modern usage.

Word Breakdown

un-
prefix meaning 'not'
prefix
+
sure
certain or confident
root
English Dictionary
さらにEnglish→Englishの単語を閲覧 →

学習進捗

学習の旅を追跡しましょう!

• 語彙を構築するために単語を保存

• 日々の連続記録を監視

• パーソナライズされた復習リマインダーを取得

• 学習済み単語の統計を確認

高度な機能にアクセスして進捗を追跡するにはログインしてください!

ダッシュボードへ →

年間言葉

その年を象徴する最も注目すべき言葉。私たちの世界を形作った語彙を発見しよう。