1. in a manner that is frivolous, capricious, or lacking in seriousness or steadiness
Usage: often describes behavior or speech that is lighthearted or not thoughtful
2. in a manner characterized by instability or a tendency to change quickly; inconstantly
Usage: describes actions or attitudes that are fickle or unreliable

Examples

• She flightily dismissed the serious proposal without giving it proper consideration.
• He spoke flightily about his future plans, changing his mind every few days.
• The committee flightily moved from one agenda item to another without reaching any decisions.
• She flightily agreed to the commitment, only to back out the following week.
• He treated the matter flightily, as if it were merely a joke.
• The group flightily abandoned their original strategy in favor of a new one.