shear stress

This term is a technical expression used primarily in physics, materials science, and structural engineering. It describes a specific mechanical action where forces act tangentially to a cross-section, contrasting with normal stress, which acts perpendicularly to the surface. The conceptual image is one of sliding or slicing, similar to how scissors cut paper.

Because it refers to a specific physical property or state of tension within a material, it is treated as an uncountable noun. It is almost always used in a technical register and is rarely found in casual conversation unless discussing engineering or geological phenomena like tectonic plate movement.