Mesh

The term mesh is commonly used with two meanings:

• In a two-dimensional pattern possessing rotational symmetry, the rotation points constitute the nodes of a net and divide the plane into regions that are called meshes. The number of meshes meeting at any rotation point equals twice the order of the rotation at that point.
• A two-dimensional unit cell is also sometimes called a mesh.

According to Loeb (1971), only the first use would be correct.

Reference

• Loeb, A. B. (1971). Color and symmetry. New York: Wiley-Interscience.