Context: My heels clop up the winding stone staircase and my hamstrings tugged.
Source: Adebayo,D.,B. Morrison and J. Rogers(eds). New writing 12. London: Picator/British Councils, 2003.

Definition: if a horse clops, its hooves make a loud sound as they touch the ground.
Source:Longman Dictionary Contemporary English (2005), Person Education Limited