1. in a way that is brief, fleeting, or not thorough; casually or superficially
2. in a manner that passes by or goes past; in passing
Usage: somewhat archaic or literary

Examples

• She mentioned the problem only passingly during the meeting.
• He passingly glanced at the newspaper before heading to work.
• The novel passingly references historical events without exploring them deeply.
• They discussed the topic passingly, without reaching any real conclusions.
• She was passingly familiar with the subject, having read about it once or twice.