simple

having few parts; not complex or complicated or involved

• “a simple problem”
• “simple mechanisms”
• “a simple design”
• “a simple substance”

easy and not involved or complicated

• “an elementary problem in statistics”
• “elementary, my dear Watson”
• “a simple game”
• “found an uncomplicated solution to the problem”

apart from anything else; without additions or modifications

• “only the bare facts”
• “shocked by the mere idea”
• “the simple passage of time was enough”
• “the simple truth”

exhibiting childlike simplicity and credulity

• “childlike trust”
• “dewy-eyed innocence”
• “listened in round-eyed wonder”

lacking mental capacity and devoid of subtlety

(botany) of leaf shapes; of leaves having no divisions or subdivisions

not elaborate in style; unornamented

• “a simple country schoolhouse”
• “her black dress--simple to austerity”

any herbaceous plant having medicinal properties

a person lacking intelligence or common sense