unsure

Unsure is an English adjective describing a state of not being certain. It conveys doubt, hesitancy, or a lack of confidence about a person, decision, outcome, or proposition. In everyday use, unsure often precedes prepositional phrases such as about, of, or with a clause introduced by whether or if.

For example: "I am unsure about the plan," "She is unsure of the next step," or "They were unsure whether to proceed." In formal writing, the synonym uncertain is common when the emphasis is on lack of information rather than personal doubt; unsure can sound more subjective or conversational.

Compared with related terms, unsure highlights personal doubt; uncertain emphasizes an objective lack of information or forecast; unclear indicates a lack of clarity in a statement or evidence. Hesitant and indecisive describe delays or difficulty in deciding, while unsure can be a momentary state rather than a trait.

Etymology: the word is formed by adding the negating prefix un- to the adjective sure, itself derived from older sources meaning confident or certain.

Usage notes: Unsure is versatile but less precise than uncertain when technical or analytical language is required. In reporting or formal instruction, writers may choose "uncertain" or "not certain" to avoid ambiguity about a speaker's confidence.

See also: uncertainty, sure, certain, unclear, hesitant, indecisive.