Shear

Shear as a noun could mean:
Bias (textile), in clothing design, fabric may be cut on the shear
Cosmic shear, an effect of distortion of image of distant galaxies due to deflection of light by matter, as predicted by general relativity (see also weak lensing and gravitational lens)
Geological shear, a form of fault
Guillotine (metalwork), also called a shear, a machine used to cut sheet metal
Shear line (locksmithing), in lockpicking, where the inner cylinder ends and the outer cylinder begins in a cylinder lock
Shear line (meteorology), an area of wind shear
Shear (mathematics), a particular kind of linear mapping, also called transvections
Shear stress in physics, refers to a stress state that will cause shearing (see verb below) when it exceeds a material's shear strength,
Wind shear, a difference in wind speed or direction between two wind currents in the atmosphere

Shear as a verb or shearing could mean:
Sheep shearing, the process of removing the wool from a sheep
Shearing interferometer, in optics, a simple and very common means to check the collimation of beams by observing interference
Shearing (physics), the deformation of a material substance in which parallel internal surfaces slide past one another,
Skin, specifically, the tearing and splitting of the layers