Just 2 percent of users donating can help bring in more developers to keep Blender the best 3D software out there. Free for everyone, forever!
Reference
Edit Mode
Toolbar ‣ Rip
V
The Rip tool separates UV components (vertices, edges, faces) from connected components. The components are ripped in the direction of the mouse pointer position.
Before.¶
After.¶
See also
Mesh editing Rip operation.