Synonyms for Clop (same or very similar meaning)
WordNet sense 1 (the sound of a horse's hoofs hitting on a hard surface):
clip-clop, clippety-clop, clopping, clumping, clunkingWordNet sense 2 (make or move along with a sound as of a horse's hooves striking the ground):
clump, clunk, plunkFrom the ODE community, based on WordNetadd/edit