flippant

"Young women were taught that flippancy did not become them when I was young," he rebuked.

You must excuse my flippancy, for I am writing I know not what, to escape from myself.

But Mrs. Dodd did not condescend to reprove him; she forgave the flippancy of the remark for the sake of the compliment.

Herrick refrained from the flippancy of replying, "Wonderful weather for the time of year!"