Plainness/ˈpleɪnnəs/ Definition 1 of 3Pro Tip 1/3Visual Simplicity Refers to things that look simple or bare, usually in art or design. The painting's plainness gives it a serene feel. Pro Tip 2/3Not Fancy Used for items or styles without decoration or elaborate details. She preferred plainness in her clothing, avoiding bright patterns. Pro Tip 3/3Not Complicated When something is straightforward and uncomplicated. The architect's design was noted for its plainness.