Definition of "quickening"
An increase of speed.
Quotations
It resembled them in the sense that it was not ended, when it was past, but continued to unfold, in Watt's head, from beginning to end, over and over again, the complex connexions of its lights and shadows, the passing from silence to sound and from sound to silence, the stillness before the movement and the stillness after, the quickenings and retardings, the approaches and the separations, all the shifting detail of its march and ordinance, according to the irrevocable caprice of its taking place.
1953, Samuel Beckett, Watt, Olympia Press