General:
* V-notch: This is the most straightforward term.
* V-shaped incision: This emphasizes the shape of the cut.
* V-shaped opening: This describes the resulting shape after the cut.
Specific to context:
* Cleavage: Used for a V-shaped neckline in clothing.
* Notch: A small, V-shaped cut on an object's edge (like a garment, wood, or metal).
* Wedge: When the V-shaped cut is larger and forms a triangular shape.
* Slit: A long, narrow V-shaped cut, often used in clothing.
Technical:
* Bevel: A slanted surface, often created with a V-shaped cut.
* Chamfer: A small, V-shaped cut made to reduce sharpness.
The best word to use will depend on the specific context and the intended meaning.