n. The quality or state of being simple, unmixed, or uncompounded; as, the simplicity of metals or of earths.n. The quality or state of being not complex, or of consisting of few parts; as, the simplicity of a machine.n. Artlessness of mind; freedom from cunning or duplicity; lack of acuteness and sagacity.n. Freedom from artificial ornament, pretentious style, or luxury; plainness; as, simplicity of dress, of style, or of language; simplicity of diet; simplicity of life.n. Freedom from subtlety or abstruseness; clearness; as, the simplicity of a doctrine; the simplicity of an explanation or a demonstration.n. Weakness of intellect; silliness; folly.n. An act or instance of foolishness.