Definition of faithless

• a. - Not believing; not giving credit.
• a. - Not believing on God or religion; specifically, not believing in the Christian religion.
• a. - Not observant of promises or covenants.
• a. - Not true to allegiance, duty, or vows; perfidious; trecherous; disloyal; not of true fidelity; inconstant, as a husband or a wife.
• a. - Serving to disappoint or deceive; delusive; unsatisfying.