1. (a.) Not certain; not having certain knowledge; not assured in mind; distrustful.

2. (a.) Irresolute; inconsonant; variable; untrustworthy; as, an uncertain person; an uncertain breeze.

3. (a.) Questionable; equivocal; indefinite; problematical.

4. (a.) Not sure; liable to fall or err; fallible.

5. (v.) To make uncertain.