bottomless

adjective
  1. Having no bottom or seeming to have no end; immeasurably deep. adjective
    The well appeared to be bottomless, as no one could find its end.
    She felt like she was falling into a bottomless pit of despair.
  2. Unlimited or inexhaustible; having no limit or end. adjective
    The restaurant offers a bottomless cup of coffee, allowing patrons to drink as much as they want.
    He seemed to have a bottomless supply of energy, never tiring from the day's activities.