1. the quality or state of being simple; lack of complexity or difficulty
2. lack of intelligence or mental capacity; foolishness
Usage: somewhat archaic

Examples

• The simpleness of the design made it easy to understand.
• She appreciated the simpleness of country living.
• The instructions were written with admirable simpleness.
• His simpleness in business matters often led to poor decisions.
• The simpleness of the recipe made it perfect for beginners.
• The child’s simpleness was both endearing and concerning to his teachers.