1. (a.) Not believing; not giving credit.

2. (a.) Not believing on God or religion; specifically, not believing in the Christian religion.

3. (a.) Not observant of promises or covenants.

4. (a.) Not true to allegiance, duty, or vows; perfidious; treacherous; disloyal; not of true fidelity; inconstant, as a husband or a wife.

5. (a.) Serving to disappoint or deceive; delusive; unsatisfying.