Long and narrow indentation in a part/material, usually for other parts to fit into
In manufacturing or mechanical engineering a groove is a long and narrow indentation built into a material, generally for the purpose of allowing another material or part to move within the groove and be guided by it. Examples include:
A canal cut in a hard material, usually metal. This canal can be round, oval or an arc in order to receive another component such as a boss, a tongue or a gasket. It can also be on the circumference of a dowel, a bolt, an axle or on the outside or inside of a tube or pipe etc. This canal may receive a circlip, an o-ring, or a gasket.
A depression on the entire circumference of a cast or machined wheel, a pulley or sheave. This depression may receive a cable, a rope or a belt.