Demure (adjective)

1. Quiet, serious, and reserved.
2. Modest and reserved in behavior; not showy or bold.

Origin:

Late 16th century: from french demure, from old french demourer "remain", from latin demorari "to delay", from de- "away" + morari "to delay".

Examples:

1. She was always demure and polite.
2. The young girl was demure and shy.
3. He was demure in his manner and appearance.
4. The demure young woman was always dressed modestly.
5. She was demure and always kept to herself.