faithless

Adjective

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, double-crossing, double-dealing, double-faced, double-hearted

6. Serving to disappoint or deceive

   Synonyms:

   delusive, unsatisfying