The steady chug-chug and puff-puff of the motor was heard as the adventurers moved on up the mountain.
"puff-puff," slowly at first, in a solemn and majestic manner.
We wanted to get away from clang-clang and honk-honk and puff-puff.
It was a steady "puff-puff," and then the darkness was cut by a glare of light.
The chatter of the gasoline engine came to her faintly, puff-puff.
Then he began to jump up and down on the top of me, and explained that he was “riding in the puff-puff.”
My nurse—an egregious female—had previously remarked, "The dear child do take such notice of the puff-puff!"
From the boat yard came the sound of mallet and caulking iron, and the steady puff-puff, puff-puff of the machine-shop exhaust.