What does unsure mean?
Unsure means not certain or confident about something. It is used when a person lacks sufficient information, cannot confidently predict an outcome, or is hesitant about making a choice. For example, someone may be unsure whether a message arrived, unsure which route to take, or unsure whether another person agrees. The word has no strongly negative connotation; it straightforwardly communicates doubt rather than fear, confusion, or refusal. In many contexts, unsure and uncertain are nearly interchangeable, although unsure can also convey a person's tentative or less confident attitude more directly. It is especially useful when the degree of doubt matters: while saying that something is wrong states a conclusion, saying that someone is unsure about it identifies doubt as the speaker's present state. The word appears naturally in expressions such as “unsure about,” “unsure whether,” and “unsure of,” and it is equally suitable in conversation, academic writing, reports, and formal decisions.
adjectiveNot certain or confident about something. It may indicate doubt about a fact, a decision, or how to act.
- Not certain about a fact, outcome, decision, or course of action.
- Lacking confidence in one's judgment, ability, or expectations.
"She was unsure whether to accept the offer."
"The researchers remain unsure how the ancient structure was built."
"I felt unsure about making the change so soon."
One small prefix tells the whole story: un- negates sure, turning certainty into doubt.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does unsure come from?
Unsure entered English in the late 16th century through the combination of the negating prefix un- and the word sure. Sure came into Middle English from Old French seür, ultimately from Latin secūrus, meaning “safe” or “secure.” Related English words such as secure, assure, ensure, and insure also reflect this Latin foundation.
Related word forms
How unsure is actually used
Unsure is neutral in register and common in speech and formal writing. It can describe either a lack of factual certainty or a lack of personal confidence.
Easily confused with unsure
Unsure means not certain, whereas assure means to make someone else certain or confident.