Groove

A furrow, channel, or long hollow, such as may be formed by cutting, molding, grinding, the wearing force of flowing water, or constant travel; a depressed way; a worn path; a rut.

Hence: The habitual course of life, work, or affairs; fixed routine.

A shaft or excavation.

To cut a groove or channel in; to form into channels or grooves; to furrow.

(anatomy) any furrow or channel on a bodily structure or part