Something going flip-flap in the night.    From Wordnet, Princeton University. 

Verb (used without object) : The opposition claimed that the President had flip-flopped on certain issues. ,The door flip-flopped in the high wind.    From Dictionary.com. 

People flitted by like black shadows in the dark streets, and their shoes went flip-flap on the greasy pavements.    From Wordnik.com.  [Maigret and the Man on the Bench]

When he did a round off a flip-flap and a high back somersault, a row of head-sets across the ring, finishing by doing heels in the mud, Alfred turned green with envy.    From Wordnik.com.  [Watch Yourself Go By] Reference

At its dormer window she stood listening to the coorooing of the fantails and the sudden flutter and flip-flap of their wings climbing the air from the yew-hedged garden.    From Wordnik.com.  [Over the River] Reference

flip-flap, flip-flap went her footfalls through the still heat of the day, and persistently, incurably, her umbrella sought to slip from under the elbow that retained it.    From Wordnik.com.  [The Food of the Gods and how it came to Earth] Reference

"And I don't do another flip-flap," put in the clown.    From Wordnik.com.  [The Rover Boys on the River The Search for the Missing Houseboat] Reference

To my wonder I don't turn no flip-flap, but performs like a draw-shot in billiards.    From Wordnik.com.  [Wolfville Nights] Reference

One could hear the flip-flap of their slippers all over the place, and at all hours.    From Wordnik.com.  [Here are Ladies] Reference

But I heard his observation on the weather, and the flip-flap of his tail on the ground.    From Wordnik.com.  [Travels in West Africa] Reference

And after doing a flip-flap, he continued: "Mr. Ringmaster, what's the difference between your knife and me?".    From Wordnik.com.  [The Rover Boys on the River The Search for the Missing Houseboat] Reference

It was just what they needed to cheer them up a bit after what they had seen; for that flip-flap of mine had broken the neck of Jerome Bowles seven miles away!.    From Wordnik.com.  [The Collected Works of Ambrose Bierce, Volume 8 Epigrams, On With the Dance, Negligible Tales] Reference

"Say! it makes me feel as happy as a clown in a circus," declared Andy, and, in high spirits, he began a jig and ended by turning a flip-flap over one of the beds.    From Wordnik.com.  [The Rover Boys on a Hunt or The Mysterious House in the Woods] Reference

The splashing and trickling of taps, the flip-flap of wet slippers on a wet floor, and the low murmur of conversation, filtered through glass doors, made an appropriately drowsy accompaniment to the scene.    From Wordnik.com.  [When William Came] Reference

Talked a lot of flip-flap flub-doodle, but Ham was all through with the proud-popper business, and the young man found him as full of knots as a hickory root, and with a hide that would turn the blade of an ax.    From Wordnik.com.  [Old Gorgon Graham]

I was not aware at first of the exact state of my feelings -- for I had never been in love more than three or four times in all my life -- but I did know that at her request I would have been proud to stand on my head, or turn a flip-flap into the Scheldt.    From Wordnik.com.  [In Search of the Unknown] Reference

Then she said, "Oh, I want to go on the flip-flap.    From Wordnik.com.  [The Lee Shore] Reference

It is just simply the ordinary sentimental flip-flap that a French versifier can turn out by the yard. ".    From Wordnik.com.  [Mrs. Warren's Daughter A Story of the Woman's Movement] Reference

"You would think, to look at him," Urquhart said to Lucy, "that he had been going in extensively for the flip-flap this afternoon.    From Wordnik.com.  [The Lee Shore] Reference

The scent of curry was in their nostrils; the regular "flip-flap" of the deftly turned chupattie was in their ears; when a flying order had come from the house -- "The.    From Wordnik.com.  [Captain Desmond, V.C.] Reference

“Khák-bák,” an onomatopœia like our flip-flap and.    From Wordnik.com.  [The Book of The Thousand Nights And A Night] Reference

He lay very still in bed with the life fading out of him -- suddenly sprung out of it, threw what is professionally called a flip-flap, and fell dead on the floor. ".    From Wordnik.com.  [The Life of Charles Dickens, Vol. I-III, Complete] Reference

"Khák-bák," an onomatopœia like our flip-flap and.    From Wordnik.com.  [Arabian nights. English] Reference

With a flip-flap noise.    From Wordnik.com.  [Gizmodo] Reference

A flip-flap on the blotting paper.    From Wordnik.com.  [Peck's Sunshine Being a Collection of Articles Written for Peck's Sun, Milwaukee, Wis. - 1882] Reference

"Ready, now!" and on he went, smashing away the boughs before him, while ever and anon I heard his cheery voice, calling or whistling to his dogs, or rousing up the tenants of some thickets into which even he could not force his way; and I, creeping, as best I might, among the tangled brush, now plunging half thigh deep in holes full of tenacious mire, now blundering over the moss-covered stubs, pressed forward, fancying every instant that the rustling of the briers against my jacket was the flip-flap of a rising woodcock.    From Wordnik.com.  [Warwick Woodlands Things as they Were There Twenty Years Ago] Reference