1. most inappropriate or improper in behavior, appearance, or conduct
Usage: superlative form of unseemly

Examples

• His was the unseemliest behavior at the formal dinner.
• The unseemliest comments came from those who should have known better.
• She displayed the unseemliest conduct during the ceremony.
• The unseemliest attire was worn by the guest who arrived late.
• It was the unseemliest time to bring up such a controversial topic.
• The unseemliest laughter erupted during the solemn moment.