ritmo, m., rhythm.
rival, m., rival.
rivalizar, to be rivals; to vie (entre sí, with each other).
rizar, to curl, crisp, ripple.
rizo, m., curl.
roca, f., rock, cliff.
roce, m., touch, rustle, rustling.
rocín, m., hack, horse, nag.
rocío, m., dew.
rodar, to roll, move along, rotate, revolve, roll down hill.