Behaving in a polite or well-mannered way

शिष्टता से व्यवहार करना

English Usage: The children were mannerly during the dinner.

Hindi Usage: बच्चों ने रात्रिभोजन के दौरान शिष्टता से व्यवहार किया।

In a manner that is polite or behaves well

शिष्टता पूर्वक

English Usage: She spoke mannerly to the guests.

Hindi Usage: उसने मेहमानों से शिष्टता पूर्वक बात की।