Mainly describes things that are spherical (round like a ball) and large. For small objects, you can use 'elul ('eluuch) "is round small object". May be used to describe something as "round" even if it is not perfectly spherical.
Mesa Grande dictionary also defines as, "in a circle"
"Round and circular", like a wheel or donut, is tepechuurp
"Round and flat", like a coin, is yareyar (large object) or yarreyarr (small object)