頭あたまの冴さえ

noun

mental sharpness; clarity of mind; bright intelligence

Refers to a state where one's thinking is clear, quick, and effective. Often used when describing good mental condition, especially after rest or when focused.

• 朝あさは頭あたまの冴さえが違ちがう。

  My mind is sharper in the morning.

• 十じゅう分ぶんな睡すい眠みんが頭あたまの冴さえを取とり戻もどす。

  Adequate sleep restores mental clarity.