• 簡単かんたん — simple; easy
• 簡素かんそ — simplicity; plainness
• 簡略かんりゃく — abridgment; simplification
• 簡易かんい — simple; convenient
• 簡潔かんけつ — concise; succinct
• 手簡しゅかん — letter (old term)
• 簡便かんべん — handy; easy-to-use
• 簡略化かんりゃくか — streamlining; simplification

The top ⺮ (bamboo) points to ancient bamboo slips used as writing material. The right side supplies the sound and supports meanings tied to written notes and, by extension, “simplicity” and “brevity.”

この問題もんだいは とても簡単かんたんです。
This problem is very easy.

簡素かんそな 生活せいかつを 好このむ。
He prefers a simple lifestyle.