faithless

comparative more faithless · superlative most faithless

1. Lacking faith; lacking belief in something.

   "You're so faithless about pills," he said, "that I'm not going to give you any."

   1970, Margaret Wade Campbell Deland, Old Chester Days, page 58

2. Not believing in God, religion, or a comparable ideology.
3. Unfaithful (said of people, towards their partners)

   Menelaus, who fought to recover his faithless wife, has clearly rooted himself in Sparta for the remainder of his life […]

   1996, Frederick Ahl, Hanna Roisman, The Odyssey re-formed, page 283

4. Not observant of promises or covenants.
5. Not true to allegiance, duty, or vows

   Synonyms: perfidious, treacherous, disloyal, booky, dastardly, disleal, disloyal, double-crossing

6. Serving to disappoint or deceive

   Synonyms: delusive, unsatisfying