What is the term for a channel or groove that is machined into the surface of a workpiece?

The term that accurately describes a channel or groove machined into the surface of a workpiece is "slot." Slots are specifically designed to provide pathways for components, allow for fastening mechanisms, or facilitate movement within mechanical assemblies. They have precise dimensions and can serve multiple functions depending on their design and placement within the workpiece.

While other choices may seem related, they do not specifically define the type of feature a slot represents. A recess refers to a depression or area that is lower than the surrounding surface, often used for mounting or accommodation of parts but not necessarily a continuous groove. An indentation is typically a shallow mark or impression rather than a channel, and a channel, though similar, is more commonly used in contexts involving fluid flow or larger cutouts rather than the specific narrower definition applicable to slots in machining.