From BiblePortal Wikipedia

Webster's Dictionary [1]

(1): ( a.) To make uncertain.

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

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

(4): ( a.) Questionable; equivocal; indefinite; problematical.

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

King James Dictionary [2]

Uncer'Tain, a.

1. Not certain doubtful not certainly known. it is uncertain who will be the next president. 2. Doubtful not having certain knowledge.

man without the protection of a superior Being - is uncertain of every thing that he hopes for.

3. Not sure in the consequence.

Or whistling slings dismiss'd the uncertain stone.

4. Not sure not exact.

Soon bent his bow, uncertain in his aim.

5. Unsettled irregular.