What is the meaning of simple?

noun

• Any herbaceous plant having medicinal properties.
• A person lacking intelligence or common sense.
  • synonyms: simpleton

adjective

• Having few parts; not complex or complicated or involved.
  • usage: "a simple problem"; "simple mechanisms"; "a simple design"; "a simple substance"
• Easy and not involved or complicated.
  • usage: "an elementary problem in statistics"; "elementary, my dear Watson"; "a simple game"; "found an uncomplicated solution to the problem"
  • synonyms: elementary, uncomplicated, unproblematic
• Apart from anything else; without additions or modifications.
  • usage: "only the bare facts"; "shocked by the mere idea"; "the simple passage of time was enough"; "the simple truth"
  • synonyms: bare, mere
• Exhibiting childlike simplicity and credulity.
  • usage: "childlike trust"; "dewy-eyed innocence"; "listened in round-eyed wonder"
  • synonyms: childlike, wide-eyed, round-eyed, dewy-eyed
• Lacking mental capacity and subtlety.
  • synonyms: dim-witted, simple-minded
• Botany) of leaf shapes; of leaves having no divisions or subdivisions.
  • synonyms: unsubdivided
• Unornamented.
  • usage: "a simple country schoolhouse"; "her black dress-simple to austerity"