When it comes to describing the rhythmic sound of a horse's hooves hitting the ground, "clippety-clop" is the traditional phrase that comes to mind. However, there are a variety of other synonyms that can be used to express this sound. Some of these include "clop-clop," "clatter," "clip-clop," "thud-thud," "thump-thump," "patter," and "pat-pat." Each of these words paints a slightly different picture of the sound, and can be used to add variety and depth to your writing. Whether you are describing a carriage ride through the countryside or a horse race, it's important to choose the right word to capture the essence of the moment.