Fly-away

Dave was as steady and solid as she was fickle and fly-away, and in some way Dave, who never doubted anybody, doubted her.

Source: wiktionary

It's a breath of old times, alas! all forgotten in these fly-away days.

Source: wiktionary

‘Aunt Maggie, why was I ever called Jessamy?’ [...] Her aunt changed the heavy suitcase to the other hand and said, ‘It was your mother’s name.’ Jessamy’s heart gave a little jump inside her, and Aunt Maggie went on: ‘When I said I thought it was too fly-away, and wouldn’t Ann or Mary be more sensible, she said that the eldest daughter was always called Jessamy in her family.’

Source: wiktionary

See also quotations at flyaway

Source: wiktionary