1. lacking in seriousness or steadiness; frivolous or irresponsible
Usage: informal; often used to describe a person's behavior or character
2. tending to change one's mind or affections easily; fickle
Usage: informal

Examples

• She has a flighty personality and never sticks with one hobby for long.
• His flighty behavior made it hard for his friends to trust him.
• The flighty actress changed her mind about the role three times in one week.
• Don't be so flighty about your commitments; people are counting on you.
• He accused her of being flighty because she kept switching between different boyfriends.
• The flighty student forgot to turn in her assignment again.